Efficacy and safety of artemether-lumefantrine compared with quinine in pregnant women with uncomplicated Plasmodium falciparum malaria: an open-label, randomised, non-inferiority trial

Comparative efficacy of sulphadoxine-pyrimethamine and dihydroartemisinin-piperaquine against malaria infection during late-stage pregnancy in mice

The introduction of artemisinin combination therapies (ACTs) against malaria infections opened up a window of possibilities to combat malaria in pregnancy. However, the usefulness of ACTs in all stages of pregnancy must be critically assessed. This study was designed to evaluate dihydroartemisinin-piperaquine (DHAP) as a suitable alternative to sulphadoxine-pyrimethamine (SP) in the treatment of malaria during third-trimester pregnancy in mice. Experimental animals were inoculated with a parasitic dose of 1x10⁶Plasmodium berghei (ANKA strain) infected erythrocytes and randomly allocated into treatment groups. The animals received standard doses of chloroquine alone (CQ)[10 mg/kg], SP [25 mg/kg] and [1.25 mg/kg] and DHAP [4 mg/kg] and [18 mg/kg] combinations. Maternal and pupil survival, litter sizes, pup weight and still-births were recorded, while the effect of the drug combinations on parasite suppression, recrudescence and parasite clearance time were evaluated. The day 4 chemo-suppression of parasitemia by DHAP in infected animals was comparable to SP, and CQ treatment (P > 0.05). The mean recrudescence time was significantly delayed (P = 0.031) in the DHAP treatment group compared to the CQ treatment group, while, there was no recrudescence in animals treated with SP. The birth rate in the SP group was significantly higher than in the DHAP group (P < 0.05). There was 100% maternal and pup survival in both combination treatments comparable with the uninfected gravid controls. The overall parasitological activity of SP against Plasmodium berghei in late-stage pregnancy appeared better than DHAP. In addition, SP treatment resulted in better birth outcomes assessed compared to DHAP treatment.

Safety of Treating Malaria with Artemisinin-Based Combination Therapy in the First Trimester of Pregnancy

There have been recent calls for the use of artemisinin-based combination therapies (ACTs) for uncomplicated malaria in the first trimester of pregnancy. Nevertheless, the 2021 WHO Guidelines for Malaria reaffirmed their position that there is not adequate clinical safety data on artemisinins to support that usage. The WHO's position is consistent with several issues with the existing clinical data. First, first trimester safety results from multiple ACTs were lumped in a meta-analysis which does not demonstrate that each of the included ACTs is equally safe. Second, safety results from all periods of the first trimester were lumped in the meta-analysis which does not demonstrate the same level of safety for all subperiods, particularly gestational Weeks 6 to 8 which is likely to be the most sensitive period. Third, even if there is evidence of a lack of an effect on miscarriage for a particular ACT, it does not follow then there are no developmental effects for any ACT. In monkeys, artesunate caused marked embryonal anemia leading to embryo death but the long-term consequences of lower levels of embryonal anemia are not known. Fourth, there have been advances in the sensitivity and usage of rapid diagnostic tests that will lead to diagnoses of malaria earlier in gestation which is less well studied and more likely sensitive to artemisinins. Any clinical studies of the safety of ACTs in the first trimester need to evaluate the results of treatment with individual ACTs during different 1- to 2-week periods of the first trimester.

The Changing Climate and Pregnancy Health

PURPOSE OF REVIEW

Climate change is the biggest public health threat of the twenty-first century but its impact on the perinatal period has only recently received attention. This review summarizes recent literature regarding the impacts of climate change and related environmental disasters on pregnancy health and provides recommendations to inform future adaptation and mitigation efforts.

RECENT FINDINGS

Accumulating evidence suggests that the changing climate affects pregnancy health directly via discrete environmental disasters (i.e., wildfire, extreme heat, hurricane, flood, and drought), and indirectly through changes in the natural and social environment. Although studies vary greatly in design, analytic methods, and assessment strategies, they generally converge to suggest that climate-related disasters are associated with increased risk of gestational complication, pregnancy loss, restricted fetal growth, low birthweight, preterm birth, and selected delivery/newborn complications. Window(s) of exposure with the highest sensitivity are not clear, but both acute and chronic exposures appear important. Furthermore, socioeconomically disadvantaged populations may be more vulnerable. Policy, clinical, and research strategies for adaptation and mitigation should be continued, strengthened, and expanded with cross-disciplinary efforts. Top priorities should include (a) reinforcing and expanding policies to further reduce emission, (b) increasing awareness and education resources for healthcare providers and the public, (c) facilitating access to quality population-based data in low-resource areas, and (d) research efforts to better understand mechanisms of effects, identify susceptible populations and windows of exposure, explore interactive impacts of multiple exposures, and develop novel methods to better quantify pregnancy health impacts.

Efficacy and Safety of Artemisinin-Based Combination Therapy for the Treatment of Uncomplicated Malaria in Pregnant Women: A Systematic Review and Meta-Analysis

Introduction

Malaria is one of the infectious diseases with substantial risks for pregnant women, the fetus and the newborn child. Thus, prevention and treatment of malaria with safe and effective drugs is of paramount importance. Pregnant women are mostly excluded from clinical trials, and systematic approaches of pharmacovigilance in pregnancy are limited. This means the safety and efficacy of antimalarial agents during pregnancy are unclear.

Purpose

This study was designed to carry out a systematic review and aggregate data meta-analysis of literature published on efficacy and safety of artemisinin-based combination therapy (ACT) for uncomplicated malaria in pregnant women.

Methods

A search of literature published between 1998 to 2020 on efficacy and safety of artemisinin-based combination therapy (ACT) in pregnant women was made using Cochrane Library, Medline and the Malaria in Pregnancy Consortium Library. Data were extracted independently by two reviewers, and any discrepancies were resolved by consensus. Meta-analysis was carried out using Open Meta-Analyst software. Random effects model was applied, and the heterogeneity of studies was evaluated using Higgins I².

Results

Twenty-four studies that fulfilled the inclusion criteria were included in the final assessment. Overall, days 28 to 63 malaria treatment success rate was 96.1%. Overall days 28 to 63 cure rates for AL, AS+AQ, AS+MQ, DHA+PQ, AS+ATQ+PG and AS+SP were 95.1%, 92.2%, 97.0%,94.3%, 96.5% and 97.4%, respectively. Comparison of ACTs with non-ACTs revealed that the risk of treatment failure was substantially lower in patients treated with ACTs than with non-ACTs (risk ratio 0.20, 95% C.I. 0.09–0.43). The overall prevalences of miscarriage, stillbirth and congenital anomalies were 0.3%, 2.1% and 1.0%, respectively, and found to be comparable among various ACTs. There was comparable tolerability across ACTs during pregnancy.

Conclusion

ACTs demonstrated a high cure rate, safety and tolerability against Plasmodium falciparum infection in pregnant women. The higher treatment success and comparable tolerability could be used as an input for decision makers to support the continued usage of ACTs for treatment of uncomplicated falciparum malaria in pregnant women.

Randomized Controlled Trial of the Electrocardiographic Effects of Four Antimalarials for Pregnant Women with Uncomplicated Malaria on the Thailand-Myanmar Border

Quinoline antimalarials cause drug-induced electrocardiograph QT prolongation, a potential risk factor for torsade de pointes. The effects of currently used antimalarials on the electrocardiogram (ECG) were assessed in pregnant women with malaria.

Quinoline antimalarials cause drug-induced electrocardiographic QT prolongation, a potential risk factor for torsade de pointes. The effects of currently used antimalarials on the electrocardiogram (ECG) were assessed in pregnant women with malaria. Pregnant women with microscopy-confirmed parasitemia of any malaria species were enrolled in an open-label randomized controlled trial on the Thailand-Myanmar border from 2010 to 2016. Patients were randomized to the standard regimen of dihydroartemisinin-piperaquine (DP) or artesunate-mefloquine (ASMQ) or an extended regimen of artemether-lumefantrine (AL+). Recurrent Plasmodium vivax infections were treated with chloroquine. Standard 12-lead electrocardiograms were assessed on day 0, 4 to 6 h following the last dose, and day 7. QT was corrected for the heart rate by a linear mixed-effects model-derived population-based correction formula (QTcP = QT/RR^0.381). A total of 86 AL+, 82 ASMQ, 88 DP, and 21 chloroquine-treated episodes were included. No patients had an uncorrected QT interval nor QTcP of >480 ms at any time. QTcP corresponding to peak drug concentration was longer in the DP group (adjusted predicted mean difference, 17.84 ms; 95% confidence interval [CI], 11.58 to 24.10; P < 0.001) and chloroquine group (18.31 ms; 95% CI, 8.78 to 27.84; P < 0.001) than in the AL+ group, but not different in the ASMQ group (2.45 ms; 95% CI, −4.20 to 9.10; P = 0.47) by the multivariable linear mixed-effects model. There was no difference between DP and chloroquine (P = 0.91). QTc prolongation resulted mainly from widening of the JT interval. In pregnant women, none of the antimalarial drug treatments exceeded conventional thresholds for an increased risk of torsade de pointes.

Drug treatment and prevention of malaria in pregnancy: a critical review of the guidelines

Background

Malaria caused by Plasmodium falciparum in pregnancy can result in adverse maternal and fetal sequelae. This review evaluated the adherence of the national guidelines drawn from World Health Organization (WHO) regions, Africa, Eastern Mediterranean, Southeast Asia, and Western Pacific, to the WHO recommendations on drug treatment and prevention of chloroquine-resistant falciparum malaria in pregnant women.

Methods

Thirty-five updated national guidelines and the President’s Malaria Initiative (PMI), available in English language, were reviewed. The primary outcome measures were the first-line anti-malarial treatment protocols adopted by national guidelines for uncomplicated and complicated falciparum malaria infections in early (first) and late (second and third) trimesters of pregnancy. The strategy of intermittent preventive treatment of malaria in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) was also addressed.

Results

This review evaluated the treatment and prevention of falciparum malaria in pregnancy in 35 national guidelines/PMI-Malaria Operational Plans (MOP) reports out of 95 malaria-endemic countries. Of the 35 national guidelines, 10 (28.6%) recommend oral quinine plus clindamycin as first-line treatment for uncomplicated malaria in the first trimester. As the first-line option, artemether–lumefantrine, an artemisinin-based combination therapy, is adopted by 26 (74.3%) of the guidelines for treating uncomplicated or complicated malaria in the second and third trimesters. Intravenous artesunate is approved by 18 (51.4%) and 31 (88.6%) guidelines for treating complicated malaria during early and late pregnancy, respectively. Of the 23 national guidelines that recommend IPTp-SP strategy, 8 (34.8%) are not explicit about directly observed therapy requirements, and three-quarters, 17 (73.9%), do not specify contra-indication of SP in human immunodeficiency virus (HIV)-infected pregnant women receiving cotrimoxazole prophylaxis. Most of the guidelines (18/23; 78.3%) state the recommended folic acid dose.

Conclusion

Several national guidelines and PMI reports require update revisions to harmonize with international guidelines and emergent trends in managing falciparum malaria in pregnancy. National guidelines and those of donor agencies should comply with those of WHO guideline recommendations although local conditions and delayed guideline updates may call for deviations from WHO evidence-based guidelines.

Efficacy of Miltefosine and Artemether on Infected Biomphalaria Alexandrina Snails with Schistosoma Mansoni: Immunological and Histological Studies

Biomphalaria alexandrina snails have received much attention due to their great medical importance as vectors for transmitting Schistosoma mansoni infection to humans. The main objective of the present work was to assess the efficacy of miltefosin a synthetic molluscicidal drug and artemether a natural molluscicidal drug. The correlation between immunological and histological observations from light and electron microscopy of the hemocytes of B. alexandrina post treatment with both drugs was also evaluated. LC50 and LC90 values were represented by 13.80 ppm and 24.40 ppm for miltefosine and 16.88 ppm and 27.97 ppm for artemether, respectively. The results showed that the treatment of S. mansoni-infected snails and normal snails with sublethal dose of miltefosine (LC25=8.20 ppm) and artemether (LC25=11.04 ppm) induced morphological abnormalities and a significant reduction in hemocytes count.

Teratogen update: Malaria in pregnancy and the use of antimalarial drugs in the first trimester

Malaria is a particular problem in pregnancy because of enhanced sensitivity, the possibility of placental malaria, and adverse effects on pregnancy outcome. Artemisinin-containing combination therapies (ACTs) are the most effective antimalarials known. WHO recommends 7-day quinine therapy for uncomplicated Plasmodium falciparum malaria in the first trimester despite the superior tolerability and efficacy of 3-day ACT regimens because artemisinins caused embryolethality and/or cardiovascular malformations at relatively low doses in rats, rabbits, and monkeys. The developmental toxicity of artesunate, artemether, and DHA were similar in rats but artesunate was embryotoxic at lower doses in rabbits (5 mg/kg/day) than artemether (no effect level = 25 mg/kg/day). In clinical studies in Africa, treatment with artemether-lumefantrine in the first trimester was observed to be highly efficacious and the miscarriage rate (≤3.1%) was similar to no antimalarial treatment (2.6%). When data from the first-trimester use of largely artesunate-based therapies in Thailand were pooled together, there was no difference in miscarriage rate compared to quinine. However, individually, artesunate-mefloquine was associated with a higher miscarriage rate (15/71 = 21%) compared to other artemisinin-based therapies including 7-day artesunate + clindamycin (2/50 = 4%) and quinine (92/842 = 11%). Thus, appropriate statistical comparisons of individual ACT groups are needed prior to assuming that they all have the same risk for developmental toxicity. Current limitations in the assessment of the safety of ACTs in the first trimester are a lack of exposures early in gestation (gestational weeks 6-7), limited postnatal evaluation for cardiovascular malformations, and the pooling of all ACTs for the assessment of risk.

Deleterious effects of malaria in pregnancy on the developing fetus: a review on prevention and treatment with antimalarial drugs

All malaria infections are harmful to both the pregnant mother and the developing fetus. One in ten maternal deaths in malaria endemic countries are estimated to result from Plasmodium falciparum infection. Malaria is associated with a 3-4 times increased risk of miscarriage and a substantially increased risk of stillbirth. Current treatment and prevention strategies reduce, but do not eliminate, malaria's damaging effects on pregnancy outcomes. Reviewing evidence generated from meta-analyses, systematic reviews, and observational data, the first paper in this Series aims to summarise the adverse effects of malaria in pregnancy on the fetus and how the current drug treatment and prevention strategies can alleviate these effects. Although evidence supports the safety and treatment efficacy of artemisinin-based combination therapies in the first trimester, these therapies have not been recommended by WHO for the treatment of malaria at this stage of pregnancy. Intermittent preventive treatment of malaria in pregnancy with sulfadoxine-pyrimethamine is contraindicated in the first trimester and provides imperfect chemoprevention because of inadequate dosing, poor (few and late) antenatal clinic attendance, increasing antimalarial drug resistance, and decreasing naturally acquired maternal immunity due to the decreased incidence of malaria. Alternative strategies to prevent malaria in pregnancy are needed. The prevention of all malaria infections by providing sustained exposure to effective concentrations of antimalarial drugs is key to reducing the adverse effects of malaria in pregnancy.

Updated pharmacokinetic considerations for the use of antimalarial drugs in pregnant women

INTRODUCTION

The association between pregnancy and altered drug pharmacokinetic (PK) properties is acknowledged, as is its impact on drug plasma concentrations and thus therapeutic efficacy. However, there have been few robust PK studies of antimalarial use in pregnancy. Given that inadequate dosing for prevention or treatment of malaria in pregnancy can result in negative maternal/infant outcomes, along with the potential to select for parasite drug resistance, it is imperative that reliable pregnancy-specific dosing recommendations are established.

AREAS COVERED

PK studies of antimalarial drugs in pregnancy. The present review summarizes the efficacy and PK properties of WHO-recommended therapies used in pregnancy, with a focus on PK studies published since 2014.

EXPERT OPINION

Changes in antimalarial drug disposition in pregnancy are well described, yet pregnant women continue to receive treatment regimens optimized for non-pregnant adults. Contemporary in silico modeling has recently identified a series of alternative dosing regimens that are predicted to provide optimal therapeutic efficacy for pregnant women.

Efficacy and tolerability of artemisinin-based and quinine-based treatments for uncomplicated falciparum malaria in pregnancy: a systematic review and individual patient data meta-analysis

BACKGROUND

Malaria in pregnancy affects both the mother and the fetus. However, evidence supporting treatment guidelines for uncomplicated (including asymptomatic) falciparum malaria in pregnant women is scarce and assessed in varied ways. We did a systematic literature review and individual patient data (IPD) meta-analysis to compare the efficacy and tolerability of different artemisinin-based or quinine-based treatments for malaria in pregnant women.

METHODS

We did a systematic review of interventional or observational cohort studies assessing the efficacy of artemisinin-based or quinine-based treatments in pregnancy. Seven databases (MEDLINE, Embase, Global Health, Cochrane Library, Scopus, Web of Science, and Literatura Latino Americana em Ciencias da Saude) and two clinical trial registries (International Clinical Trials Registry Platform and ClinicalTrials.gov) were searched. The final search was done on April 26, 2019. Studies that assessed PCR-corrected treatment efficacy in pregnancy with follow-up of 28 days or more were included. Investigators of identified studies were invited to share data from individual patients. The outcomes assessed included PCR-corrected efficacy, PCR-uncorrected efficacy, parasite clearance, fever clearance, gametocyte development, and acute adverse events. One-stage IPD meta-analysis using Cox and logistic regression with random-effects was done to estimate the risk factors associated with PCR-corrected treatment failure, using artemether-lumefantrine as the reference. This study is registered with PROSPERO, CRD42018104013.

FINDINGS

Of the 30 studies assessed, 19 were included, representing 92% of patients in the literature (4968 of 5360 episodes). Risk of PCR-corrected treatment failure was higher for the quinine monotherapy (n=244, adjusted hazard ratio [aHR] 6·11, 95% CI 2·57-14·54, p<0·0001) but lower for artesunate-amodiaquine (n=840, 0·27, 95% 0·14-0·52, p<0·0001), artesunate-mefloquine (n=1028, 0·56, 95% 0·34-0·94, p=0·03), and dihydroartemisinin-piperaquine (n=872, 0·35, 95% CI 0·18-0·68, p=0·002) than artemether-lumefantrine (n=1278) after adjustment for baseline asexual parasitaemia and parity. The risk of gametocyte carriage on day 7 was higher after quinine-based therapy than artemisinin-based treatment (adjusted odds ratio [OR] 7·38, 95% CI 2·29-23·82).

INTERPRETATION

Efficacy and tolerability of artemisinin-based combination therapies (ACTs) in pregnant women are better than quinine. The lower efficacy of artemether-lumefantrine compared with other ACTs might require dose optimisation.

FUNDING

The Bill & Melinda Gates Foundation, ExxonMobil Foundation, and the University of Oxford Clarendon Fund.

Poor-quality antimalarials further health inequities in Uganda

Substandard and falsified medications are a major threat to public health, directly increasing the risk of treatment failure, antimicrobial resistance, morbidity, mortality and health expenditures. While antimalarial medicines are one of the most common to be of poor quality in low- and middle-income countries, their distributional impact has not been examined. This study assessed the health equity impact of substandard and falsified antimalarials among children under five in Uganda. Using a probabilistic agent-based model of paediatric malaria infection (Substandard and Falsified Antimalarial Research Impact, SAFARI model), we examine the present day distribution of the burden of poor-quality antimalarials by socio-economic status and urban/rural settings, and simulate supply chain, policy and patient education interventions. Patients incur US$26.1 million (7.8%) of the estimated total annual economic burden of substandard and falsified antimalarials, including $2.3 million (9.1%) in direct costs and $23.8 million (7.7%) in productivity losses due to early death. Poor-quality antimalarials annually cost $2.9 million to the government. The burden of the health and economic impact of malaria and poor-quality antimalarials predominantly rests on the poor (concentration index −0.28) and rural populations (98%). The number of deaths among the poorest wealth quintile due to substandard and falsified antimalarials was 12.7 times that of the wealthiest quintile, and the poor paid 12.1 times as much per person in out-of-pocket payments. Rural populations experienced 97.9% of the deaths due to poor-quality antimalarials, and paid 10.7 times as much annually in out-of-pocket expenses compared with urban populations. Our simulations demonstrated that interventions to improve medicine quality could have the greatest impact at reducing inequities, and improving adherence to antimalarials could have the largest economic impact. Substandard and falsified antimalarials have a significant health and economic impact, with greater burden of deaths, disability and costs on poor and rural populations, contributing to health inequities in Uganda.

A Randomized Controlled Trial of Three- versus Five-Day Artemether-Lumefantrine Regimens for Treatment of Uncomplicated Plasmodium falciparum Malaria in Pregnancy in Africa

Artemether-lumefantrine antimalarial efficacy in pregnancy could be compromised by reduced drug exposure. Population-based simulations suggested that therapeutic efficacy would be improved if the treatment duration was increased.

Artemether-lumefantrine antimalarial efficacy in pregnancy could be compromised by reduced drug exposure. Population-based simulations suggested that therapeutic efficacy would be improved if the treatment duration was increased. We assessed the efficacy, tolerability, and pharmacokinetics of an extended 5-day regimen of artemether-lumefantrine compared to the standard 3-day treatment in 48 pregnant women and 48 nonpregnant women with uncomplicated falciparum malaria in an open-label, randomized clinical trial. Babies were assessed at birth and 1, 3, 6, and 12 months. Nonlinear mixed-effects modeling was used to characterize the plasma concentration-time profiles of artemether and lumefantrine and their metabolites. Both regimens were highly efficacious (100% PCR-corrected cure rates) and well tolerated. Babies followed up to 1 year had normal development. Parasite clearance half-lives were longer in pregnant women (median [range], 3.30 h [1.39 to 7.83 h]) than in nonpregnant women (2.43 h [1.05 to 6.00 h]) (P=0.005). Pregnant women had lower exposures to artemether and dihydroartemisinin than nonpregnant women, resulting in 1.2% decreased exposure for each additional week of gestational age. By term, these exposures were reduced by 48% compared to nonpregnant patients. The overall exposure to lumefantrine was improved with the extended regimen, with no significant differences in exposures to lumefantrine or desbutyl-lumefantrine between pregnant and nonpregnant women. The extended artemether-lumefantrine regimen was well tolerated and safe and increased the overall antimalarial drug exposure and so could be a promising treatment option in pregnancy in areas with lower rates of malaria transmission and/or emerging drug resistance. (This study has been registered at ClinicalTrials.gov under identifier NCT01916954.)

Tissue Parasites in HIV Infection

PURPOSE OF REVIEW

The purpose of this review is to discuss the current knowledge of HIV and tissue parasite co-infection in the context of transmission enhancement, clinical characteristics, treatment, relapse, and clinical outcomes.

RECENT FINDINGS

The pathophysiology and clinical sequelae of tissue parasites in people living with HIV (PLWH) have been well described for only a handful of organisms, primarily protozoa such as malaria and leishmaniasis. Available published data indicate that the interactions between HIV and tissue parasites are highly variable depending on the infecting organism and the degree of host immunosuppression. Some tissue parasites, such as Schistosoma species, are known to facilitate the transmission of HIV. Conversely, uncontrolled HIV infection can lead to the earlier and more severe presentation of a variety of tissue parasites and can make treatment more challenging. Although much investigation remains to be done to better understand the interactions between consequences of HIV and tissue parasite co-infection, it is important to disseminate the current knowledge on this topic to health care providers in order to prevent, treat, and control infections in PLWH.

Optimal Duration of Follow-up for Assessing Antimalarial Efficacy in Pregnancy: A Retrospective Analysis of a Cohort Followed Up Until Delivery on the Thailand-Myanmar Border

Background

Follow-up for 28–42 days is recommended by the World Health Organization to assess antimalarial drug efficacy for nonpregnant populations. This study aimed to determine the optimal duration for pregnant women, as no specific guidance currently exists.

Methods

The distributions of time to recrudescence (treatment failure), confirmed by polymerase chain reaction genotyping for different antimalarial drugs in pregnancy, were analyzed by accelerated failure time models using secondary data on microscopically confirmed recurrent falciparum malaria collected in prospective studies on the Thailand–Myanmar border between 1994 and 2010.

Results

Of 946 paired isolates from 703 women, the median duration of follow-up for each genotyped recurrence (interquartile range) was 129 (83–174) days, with 429 polymerase chain reaction–confirmed recrudescent. Five different treatments were evaluated, and 382 Plasmodium falciparum recrudescences were identified as eligible. With log-logistic models adjusted for baseline parasitemia, the predicted cumulative proportions of all the recrudescences that were detected by 28 days were 70% (95% confidence interval [CI], 65%–74%) for quinine monotherapy (n = 295), 66% (95% CI, 53%–76%) for artesunate monotherapy (n = 43), 62% (95% CI, 42%–79%) for artemether–lumefantrine (AL; n = 19), 46% (95% CI, 26%–67%) for artesunate with clindamycin (n = 19), and 34% (95% CI, 11%–67%) for dihydroartemisinin–piperaquine (DP; n = 6). Corresponding figures by day 42 were 89% (95% CI, 77%–95%) for AL and 71% (95% CI, 38%–91%) for DP. Follow-up for 63 days was predicted to detect ≥95% of all recrudescence, except for DP.

Conclusions

In low-transmission settings, antimalarial drug efficacy assessments in pregnancy require longer follow-up than for nonpregnant populations.

Monthly sulfadoxine-pyrimethamine versus dihydroartemisinin-piperaquine for intermittent preventive treatment of malaria in pregnancy: a double-blind, randomised, controlled, superiority trial

BACKGROUND

Intermittent treatment with sulfadoxine-pyrimethamine, recommended for prevention of malaria in pregnant women throughout sub-Saharan Africa, is threatened by parasite resistance. We assessed the efficacy and safety of intermittent preventive treatment with dihydroartemisinin-piperaquine as an alternative to sulfadoxine-pyrimethamine.

METHODS

We did a double-blind, randomised, controlled, superiority trial at one rural site in Uganda with high malaria transmission and sulfadoxine-pyrimethamine resistance. HIV-uninfected pregnant women between 12 and 20 weeks gestation were randomly assigned (1:1) to monthly intermittent preventive treatment during pregnancy with sulfadoxine-pyrimethamine or dihydroartemisinin-piperaquine. The primary endpoint was the risk of a composite adverse birth outcome defined as low birthweight, preterm birth, or small for gestational age in livebirths. Protective efficacy was defined as 1-prevalence ratio or 1-incidence rate ratio. All analyses were done by modified intention to treat. This trial is registered with ClinicalTrials.gov, number NCT02793622.

FINDINGS

Between Sept 6, 2016, and May 29, 2017, 782 women were enrolled and randomly assigned to receive sulfadoxine-pyrimethamine (n=391) or dihydroartemisinin-piperaquine (n=391); 666 (85·2%) women who delivered livebirths were included in the primary analysis. There was no significant difference in the risk of our composite adverse birth outcome between the dihydroartemisinin-piperaquine and sulfadoxine-pyrimethamine treatment group (54 [16%] of 337 women vs 60 [18%] of 329 women; protective efficacy 12% [95% CI -23 to 37], p=0·45). Both drug regimens were well tolerated, with no significant differences in adverse events between the groups, with the exception of asymptomatic corrected QT interval prolongation, which was significantly higher in the dihydroartemisinin-piperaquine group (mean change 13 ms [SD 23]) than in the sulfadoxine-pyrimethamine group (mean change 0 ms [SD 23]; p<0·0001).

INTERPRETATION

Monthly intermittent preventive treatment with dihydroartemisinin-piperaquine was safe but did not lead to significant improvements in birth outcomes compared with sulfadoxine-pyrimethamine.

FUNDING

Eunice Kennedy Shriver National Institute of Child Health and Human Development, and Bill & Melinda Gates Foundation.

Artemisinin-based combination therapy during pregnancy: outcome of pregnancy and infant mortality: a cohort study

BACKGROUND

The World Health Organization (WHO) recommendation of treating uncomplicated malaria during the second and third trimester of pregnancy with an artemisinin-based combination therapy (ACT) has already been implemented by all sub-Saharan African countries. However, there is limited knowledge on the effect of ACT on pregnancy outcomes, and on newborn and infant's health.

METHODS

Pregnant women with malaria in four countries (Burkina Faso, Ghana, Malawi and Zambia) were treated with either artemether-lumefantrine (AL), amodiaquine-artesunate (ASAQ), mefloquine-artesunate (MQAS), or dihydroartemisinin-piperaquine (DHA-PQ); 3127 live new-borns (822 in the AL, 775 in the ASAQ, 765 in the MQAS and 765 in the DHAPQ arms) were followed-up until their first birthday.

RESULTS

Prevalence of placental malaria and low birth weight were 28.0% (738/2646) and 16.0% (480/2999), respectively, with no significant differences between treatment arms. No differences in congenital malformations (p = 0.35), perinatal mortality (p = 0.77), neonatal mortality (p = 0.21), and infant mortality (p = 0.96) were found.

CONCLUSIONS

Outcome of pregnancy and infant survival were similar between treatment arms indicating that any of the four artemisinin-based combinations could be safely used during the second and third trimester of pregnancy without any adverse effect on the baby. Nevertheless, smaller safety differences between artemisinin-based combinations cannot be excluded; country-wide post-marketing surveillance would be very helpful to confirm such findings. Trial registration ClinicalTrials.gov, NCT00852423, Registered on 27 February 2009, https://clinicaltrials.gov/ct2/show/NCT00852423.

Trends in comparative efficacy and safety of malaria control interventions for maternal and child health outcomes in Africa: a study protocol for a Bayesian network meta-regression exploring the effect of HIV and malaria endemicity spectrum

INTRODUCTION

Unprecedented global efforts to prevent malaria morbidity and mortality in sub-Saharan Africa have saved hundreds of thousands of lives across the continent in the last two decades. This study aims to determine how the comparative efficacy and safety of available malaria control interventions intended to improve maternal and child health outcomes have changed over time considering the varied epidemiological contexts on the continent.

METHODS

We will review all randomised controlled trials that investigated malaria control interventions in pregnant women in sub-Saharan Africa and were published between January 1980 and December 2018. We will subsequently use network meta-regression to estimate temporal trends in the relative and absolute efficacy and safety of Intermittent Preventive Treatments, Intermittent Screening and Treatments, Insecticide-treated bed nets, and their combinations, and predict their ranking according to their relative and absolute efficacy and safety over time. Our outcomes will include 12 maternal and 7 child mortality and morbidity outcomes, known to be associated with either malaria infection or control. We will use intention-to-treat analysis to derive our estimates and meta-regression to estimate temporal trends and the effect modification by HIV infection, malaria endemicity and Plasmodium falciparum resistance to sulfadoxine-pyrimethamine, while adjusting for multiple potential confounders via propensity score calibration.

PROSPERO REGISTRATION NUMBER

CRD42018095138.

Development of an agent-based model to assess the impact of substandard and falsified anti-malarials: Uganda case study

BACKGROUND

Global efforts to address the burden of malaria have stagnated in recent years with malaria cases beginning to rise. Substandard and falsified anti-malarial treatments contribute to this stagnation. Poor quality anti-malarials directly affect health outcomes by increasing malaria morbidity and mortality, as well as threaten the effectiveness of treatment by contributing to artemisinin resistance. Research to assess the scope and impact of poor quality anti-malarials is essential to raise awareness and allocate resources to improve the quality of treatment. A probabilistic agent-based model was developed to provide country-specific estimates of the health and economic impact of poor quality anti-malarials on paediatric malaria. This paper presents the methodology and case study of the Substandard and Falsified Antimalarial Research Impact (SAFARI) model developed and applied to Uganda.

RESULTS

The total annual economic impact of malaria in Ugandan children under age five was estimated at US$614 million. Among children who sought medical care, the total economic impact was estimated at $403 million, including $57.7 million in direct costs. Substandard and falsified anti-malarials were a significant contributor to this annual burden, accounting for $31 million (8% of care-seeking children) in total economic impact involving $5.2 million in direct costs. Further, 9% of malaria deaths relating to cases seeking treatment were attributable to poor quality anti-malarials. In the event of widespread artemisinin resistance in Uganda, we simulated a 12% yearly increase in costs associated with paediatric malaria cases that sought care, inflicting $48.5 million in additional economic impact annually.

CONCLUSIONS

Improving the quality of treatment is essential to combat the burden of malaria and prevent the development of drug resistance. The SAFARI model provides country-specific estimates of the health and economic impact of substandard and falsified anti-malarials to inform governments, policy makers, donors and the malaria community about the threat posed by poor quality medicines. The model findings are useful to illustrate the significance of the issue and inform policy and interventions to improve medicinal quality.

Adverse pregnancy outcomes between the anti-malarial drugs: Is there a difference between the drugs recommended by World Health Organization? Results of a mixed treatment comparison analysis of randomized clinical trials and cohort studies

BACKGROUND

Data regarding the relative safety profile of anti-malarial drugs in pregnancy is sparse mainly limited by the absence of head-to-head clinical trials. The present study is a network meta-analysis of safety of anti-malarial drugs used to treat malaria in pregnant women.

METHODS

A thorough literature search using the search strategy "Malaria [tiab] AND (Pregnant [tiab] OR Pregnancy [tiab])" was carried out for either randomized controlled trials or prospective cohort studies in pregnant malarial women prescribed any of the recommended anti-malarial drugs by World Health Organization (WHO) and that have reported adverse pregnancy outcomes such as miscarriage, still birth, and neonatal deaths. Odds ratio with 95% confidence interval was used as the effect estimate. Random-effects model and Markov Chain Monte Carlo simulation method was used to generate pooled estimates. Sensitivity analysis was performed excluding data from first trimester and GRADE approach was used to categorize the quality of evidence.

RESULTS

A total of 1242 papers were obtained with the search strategy, of which seven evaluating 10 treatment arms in a total of 5510 participants were included in the present meta-analysis. The pooled estimates revealed significantly lower risks of abortion with quinine and artemisinin-lumefantrine compared to dihydroartemisinin-piperaquine, artesunate with mefloquine and artesunate with amodiaquine. But when a cohort study that was conducted in the first trimester of pregnancy was excluded, no significant differences were observed in the risk of abortion between the anti-malarial drugs. No significant differences in the risk of either stillbirths or neonatal deaths were observed with any of the drugs. The quality of evidence was found to be very low due to serious limitations in both the precision and indirectness.

CONCLUSION

WHO recommended anti-malarials in pregnancy have similar risk profiles with regard to abortion, stillbirth and neonatal deaths.

Antimalarial drugs for treating and preventing malaria in pregnant and lactating women

INTRODUCTION

Malaria in pregnancy and postpartum cause maternal mortality and adverse fetal outcomes. Efficacious and safe antimalarials are needed to treat and prevent such serious consequences. However, because of the lack of evidence on fetal safety, quinine, an old and less efficacious drug has long been recommended for pregnant women. Uncertainty about safety in relation to breastfeeding leads to withholding of efficacious treatments postpartum or cessation of breastfeeding. Areas covered: A search identified literature on humans in three databases (MEDLINE, Embase and Global health) using pregnancy or lactation, and the names of antimalarial drugs as search terms. Adverse reactions to the mother, fetus or breastfed infant were summarized together with efficacies. Expert opinion: Artemisinins are more efficacious and well-tolerated than quinine in pregnancy. Furthermore, the risks of miscarriage, stillbirth or congenital abnormality were not higher in pregnancies exposed to artemisinin derivatives for treatment of malaria than in pregnancies exposed to quinine or in the comparable background population unexposed to any antimalarials, and this was true for treatment in any trimester. Assessment of safety and efficacy of antimalarials including dose optimization for pregnant women is incomplete. Resistance to sulfadoxine-pyrimethamine in Plasmodium falciparum and long unprotected intervals between intermittent treatment doses begs reconsideration of current preventative recommendations in pregnancy. Data remain limited on antimalarials during breastfeeding; while most first-line drugs appear safe, further research is needed.

Population Pharmacokinetics of Artemether, Dihydroartemisinin, and Lumefantrine in Rwandese Pregnant Women Treated for Uncomplicated Plasmodium falciparum Malaria

The artemisinin-based combination therapy artemether-lumefantrine is commonly used in pregnant malaria patients. However, the effect of pregnancy-related changes on exposure is unclear, and pregnancy has been associated with decreased efficacy in previous studies. This study aimed to characterize the population pharmacokinetics of artemether, its active metabolite dihydroartemisinin, and lumefantrine in 22 Rwandese pregnant women in their second (n = 11) or third (n = 11) trimester with uncomplicated Plasmodium falciparum malaria. These patients were enrolled from Rwamagana district hospital and received the standard fixed oral dose combination of 80 mg of artemether and 480 mg of lumefantrine twice daily for 3 days. Venous plasma concentrations were quantified for all three analytes using liquid chromatography coupled with tandem mass spectroscopy, and data were analyzed using nonlinear mixed-effects modeling. Lumefantrine pharmacokinetics was described by a flexible but highly variable absorption, with a mean absorption time of 4.04 h, followed by a biphasic disposition model. The median area under the concentration-time curve from 0 h to infinity (AUC_0-∞) for lumefantrine was 641 h · mg/liter. Model-based simulations indicated that 11.7% of the study population did not attain the target day 7 plasma concentration (280 ng/ml), a threshold associated with increased risk of recrudescence. The pharmacokinetics of artemether was time dependent, and the autoinduction of its clearance was described using an enzyme turnover model. The turnover half-life was predicted to be 30.4 h. The typical oral clearance, which started at 467 liters/h, increased 1.43-fold at the end of treatment. Simulations suggested that lumefantrine pharmacokinetic target attainment appeared to be reassuring in Rwandese pregnant women, particularly compared to target attainment in Southeast Asia. Larger cohorts will be required to confirm this finding.

Effect of Pregnancy on the Pharmacokinetic Interaction between Efavirenz and Lumefantrine in HIV-Malaria Coinfection

Artemether-lumefantrine is often coadministered with efavirenz-based antiretroviral therapy for malaria treatment in HIV-infected women during pregnancy. Previous studies showed changes in lumefantrine pharmacokinetics due to interaction with efavirenz in nonpregnant adults. The influence of pregnancy on this interaction has not been reported. This pharmacokinetic study involved 35 pregnant and 34 nonpregnant HIV-malaria-coinfected women receiving efavirenz-based antiretroviral therapy and was conducted in four health facilities in Nigeria. Participants received a 3-day standard regimen of artemether-lumefantrine for malaria treatment, and intensive pharmacokinetic sampling was conducted from 0.5 to 96 h after the last dose. Plasma efavirenz, lumefantrine, and desbutyl-lumefantrine were quantified using validated assays, and pharmacokinetic parameters were derived using noncompartmental analysis. The median middose plasma concentrations of efavirenz were significantly lower in pregnant women (n = 32) than in nonpregnant women (n = 32) at 1,820 ng/ml (interquartile range, 1,300 to 2,610 ng/ml) versus 2,760 ng/ml (interquartile range, 2,020 to 5,640 ng/ml), respectively (P = 0.006). The lumefantrine area under the concentration-time curve from 0 to 96 h was significantly higher in pregnant women (n = 27) at 155,832 ng · h/ml (interquartile range, 102,400 to 214,011 ng · h/ml) than nonpregnant women at 90,594 ng · h/ml (interquartile range, 58,869 to 149,775 ng · h/ml) (P = 0.03). A similar trend was observed for the lumefantrine concentration at 12 h after the last dose of lumefantrine, which was 2,870 ng/ml (interquartile range, 2,180 to 4,880 ng/ml) versus 2,080 ng/ml (interquartile range, 1,190 to 2,970 ng/ml) in pregnant and nonpregnant women, respectively (P = 0.02). The lumefantrine-to-desbutyl-lumefantrine ratio also tended to be lower in pregnant women than in nonpregnant women (P = 0.076). Overall, pregnancy tempered the extent of efavirenz-lumefantrine interactions, resulting in increased lumefantrine exposure. However, any consideration of dosage adjustment for artemether-lumefantrine to enhance exposure in this population needs to be based on data from a prospective study with safety and efficacy endpoints.

Artemether-lumefantrine dosing for malaria treatment in young children and pregnant women: A pharmacokinetic-pharmacodynamic meta-analysis

BACKGROUND

The fixed dose combination of artemether-lumefantrine (AL) is the most widely used treatment for uncomplicated Plasmodium falciparum malaria. Relatively lower cure rates and lumefantrine levels have been reported in young children and in pregnant women during their second and third trimester. The aim of this study was to investigate the pharmacokinetic and pharmacodynamic properties of lumefantrine and the pharmacokinetic properties of its metabolite, desbutyl-lumefantrine, in order to inform optimal dosing regimens in all patient populations.

METHODS AND FINDINGS

A search in PubMed, Embase, ClinicalTrials.gov, Google Scholar, conference proceedings, and the WorldWide Antimalarial Resistance Network (WWARN) pharmacology database identified 31 relevant clinical studies published between 1 January 1990 and 31 December 2012, with 4,546 patients in whom lumefantrine concentrations were measured. Under the auspices of WWARN, relevant individual concentration-time data, clinical covariates, and outcome data from 4,122 patients were made available and pooled for the meta-analysis. The developed lumefantrine population pharmacokinetic model was used for dose optimisation through in silico simulations. Venous plasma lumefantrine concentrations 7 days after starting standard AL treatment were 24.2% and 13.4% lower in children weighing <15 kg and 15-25 kg, respectively, and 20.2% lower in pregnant women compared with non-pregnant adults. Lumefantrine exposure decreased with increasing pre-treatment parasitaemia, and the dose limitation on absorption of lumefantrine was substantial. Simulations using the lumefantrine pharmacokinetic model suggest that, in young children and pregnant women beyond the first trimester, lengthening the dose regimen (twice daily for 5 days) and, to a lesser extent, intensifying the frequency of dosing (3 times daily for 3 days) would be more efficacious than using higher individual doses in the current standard treatment regimen (twice daily for 3 days). The model was developed using venous plasma data from patients receiving intact tablets with fat, and evaluations of alternative dosing regimens were consequently only representative for venous plasma after administration of intact tablets with fat. The absence of artemether-dihydroartemisinin data limited the prediction of parasite killing rates and recrudescent infections. Thus, the suggested optimised dosing schedule was based on the pharmacokinetic endpoint of lumefantrine plasma exposure at day 7.

CONCLUSIONS

Our findings suggest that revised AL dosing regimens for young children and pregnant women would improve drug exposure but would require longer or more complex schedules. These dosing regimens should be evaluated in prospective clinical studies to determine whether they would improve cure rates, demonstrate adequate safety, and thereby prolong the useful therapeutic life of this valuable antimalarial treatment.

Updated CDC Recommendations for Using Artemether-Lumefantrine for the Treatment of Uncomplicated Malaria in Pregnant Women in the United States

Malaria infection during pregnancy is associated with an increased risk for maternal and fetal complications. In the United States, treatment options for uncomplicated, chloroquine-resistant Plasmodium falciparum and P. vivax malaria in pregnant women are limited to mefloquine or quinine plus clindamycin (1). However, limited availability of quinine and increasing resistance to mefloquine restrict these options. Strong evidence now demonstrates that artemether-lumefantrine (AL) (Coartem) is effective and safe in the treatment of malaria in pregnancy. The World Health Organization (WHO) has endorsed artemisinin-based combination therapies (ACTs), such as AL, for treatment of uncomplicated malaria during the second and third trimesters of pregnancy and is currently considering whether to add ACTs, including AL, as an option for malaria treatment during the first trimester (2,3). This policy note reviews the evidence and updates CDC recommendations to include AL as a treatment option for uncomplicated malaria during the second and third trimesters of pregnancy and during the first trimester of pregnancy when other treatment options are unavailable. These updated recommendations reflect current evidence and are consistent with WHO treatment guidelines.

Treatment of uncomplicated and severe malaria during pregnancy

Over the past 10 years, the available evidence on the treatment of malaria during pregnancy has increased substantially. Owing to their relative ease of use, good sensitivity and specificity, histidine rich protein 2 based rapid diagnostic tests are appropriate for symptomatic pregnant women; however, such tests are less appropriate for systematic screening because they will not detect an important proportion of infections among asymptomatic women. The effect of pregnancy on the pharmacokinetics of antimalarial drugs varies greatly between studies and class of antimalarial drugs, emphasising the need for prospective studies in pregnant and non-pregnant women. For the treatment of malaria during the first trimester, international guidelines are being reviewed by WHO. For the second and third trimester of pregnancy, results from several trials have confirmed that artemisinin-based combination treatments are safe and efficacious, although tolerability and efficacy might vary by treatment. It is now essential to translate such evidence into policies and clinical practice that benefit pregnant women in countries where malaria is endemic. Access to parasitological diagnosis or appropriate antimalarial treatment remains low in many countries and regions. Therefore, there is a pressing need for research to identify quality improvement interventions targeting pregnant women and health providers. In addition, efficient and practical systems for pharmacovigilance are needed to further expand knowledge on the safety of antimalarial drugs, particularly in the first trimester of pregnancy.

Health Consequences of Environmental Exposures in Early Life: Coping with a Changing World in the Post-MDG Era

Despite overall progress toward achieving the Millennium Development Goals, large health discrepancies persist between developed and developing countries. The world is rapidly changing and the influences of societal change and climate change will disproportionately affect the world's most vulnerable populations, thus exacerbating current inequities. Current development strategies do not adequately address these disproportionate impacts of environmental exposures. The aim of this study was to propose a new framework to address the health consequences of environmental exposures beyond 2015. This framework is transdisciplinary and precautionary. It is based on identifying social and economic determinants of health, strengthening primary health systems, and improving the health of vulnerable populations. It incorporates deliberate plans for assessment and control of avoidable environmental exposures. It sets specific, measurable targets for health and environmental improvement.

Methodology of assessment and reporting of safety in anti-malarial treatment efficacy studies of uncomplicated falciparum malaria in pregnancy: a systematic literature review

Background

Considering the uncertainty of safety of anti-malarial drugs in pregnancy, efficacy studies are one of the few sources of clinical safety data. Complete safety evaluation is not usually incorporated in efficacy studies due to financial and human resource constraints. This review reports the methods used for the assessment of safety of artemisinin-based and quinine-based treatments in efficacy studies in pregnancy.

Methods

Methodology of assessment and reporting of safety in efficacy studies of artemisinin-based and quinine-based treatment in pregnancy was reviewed using seven databases and two clinical trial registries. The protocol was registered to PROSPERO (CRD42017054808).

Results

Of 48 eligible efficacy studies the method of estimation of gestational age was reported in only 32 studies (67%, 32/48) and ultrasound was used in 18 studies (38%, 18/48). Seventeen studies (35%, 17/48) reported parity, 9 (19%, 9/48) reported gravidity and 13 (27%, 13/48) reported both. Thirty-eight studies (79%, 38/48) followed participants through to pregnancy outcome. Fetal loss was assessed in 34 studies (89%, 34/38), but the definition of miscarriage and stillbirth were defined only in 11 (32%, 11/34) and 7 (21%, 7/34) studies, respectively. Preterm birth was assessed in 26 studies (68%, 26/38) but was defined in 16 studies (62%, 16/26). Newborn weight was assessed in 30 studies (79%, 30/38) and length in 10 studies (26%, 10/38). Assessment of birth weight took gestational age into account in four studies (13%, 4/30). Congenital abnormalities were reported in 32 studies (84%, 32/38). Other common risk factors for adverse pregnancy outcomes were not well-reported.

Conclusion

Incomplete reporting and varied methodological assessment of pregnancy outcomes in anti-malarial drug efficacy studies limits comparison across studies. A standard list of minimal necessary parameters to assess and report the safety component of efficacy studies of anti-malarials in pregnancy is proposed.

Electronic supplementary material

The online version of this article (10.1186/s12936-017-2136-x) contains supplementary material, which is available to authorized users.

Systematic literature review and meta-analysis of the efficacy of artemisinin-based and quinine-based treatments for uncomplicated falciparum malaria in pregnancy: methodological challenges

Background

There is no agreed standard method to assess the efficacy of anti-malarials for uncomplicated falciparum in pregnancy despite an increased risk of adverse outcomes for the mother and the fetus. The aim of this review is to present the currently available evidence from both observational and interventional cohort studies on anti-malarial efficacy in pregnancy and summarize the variability of assessment and reporting found in the review process.

Methods

Efficacy methodology and assessment of artemisinin-based treatments (ABT) and quinine-based treatments (QBT) were reviewed systematically using seven databases and two clinical trial registries (protocol registration—PROSPERO: CRD42017054808). Pregnant women in all trimesters with parasitologically confirmed uncomplicated falciparum malaria were included irrespective of symptoms. This review attempted to re-calculate proportions of treatment success applying the same definition as the standard WHO methodology for non-pregnant populations. Aggregated data meta-analyses using data from randomized control trials (RCTs) comparing different treatments were performed by random effects model.

Results

A total of 48 eligible efficacy studies were identified including 7279 treated Plasmodium falciparum episodes. While polymerase chain reaction (PCR) was used in 24 studies for differentiating recurrence, the assessment and reporting of treatment efficacy was heterogeneous. When the same definition could be applied, PCR-corrected treatment failure of ≥ 10% at any time points was observed in 3/30 ABT and 3/7 QBT arms. Ten RCTs compared different combinations of ABT but there was a maximum of two published RCTs with PCR-corrected outcomes for each comparison. Five RCTs compared ABT and QBT. Overall, the risk of treatment failure was significantly lower in ABT than in QBT (risk ratio 0.22, 95% confidence interval 0.07–0.63), although the actual drug combinations and outcome endpoints were different. First trimester women were included in 12 studies none of which were RCTs of ABT.

Conclusions

Efficacy studies in pregnancy are not only limited in number but use varied methodological assessments. In five RCTs with comparable methodology, ABT resulted in higher efficacy than QBT in the second and third trimester of pregnancy. Individual patient data meta-analysis can include data from observational cohort studies and could overcome some of the limitations of the current assessment given the paucity of data in this vulnerable group.

Electronic supplementary material

The online version of this article (10.1186/s12936-017-2135-y) contains supplementary material, which is available to authorized users.

Intermittent Preventive Treatment With Dihydroartemisinin-Piperaquine for the Prevention of Malaria Among HIV-Infected Pregnant Women

Background

Daily trimethoprim-sulfamethoxazole (TMP-SMX) and insecticide-treated nets remain the main interventions for prevention of malaria in human immunodeficiency virus (HIV)-infected pregnant women in Africa. However, antifolate and pyrethroid resistance threaten the effectiveness of these interventions, and new ones are needed.

Methods

We conducted a double-blinded, randomized, placebo-controlled trial comparing daily TMP-SMX plus monthly dihydroartemisinin-piperaquine (DP) to daily TMP-SMX alone in HIV-infected pregnant women in an area of Uganda where indoor residual spraying of insecticide had recently been implemented. Participants were enrolled between gestation weeks 12 and 28 and given an insecticide-treated net. The primary outcome was detection of active or past placental malarial infection by histopathologic analysis. Secondary outcomes included incidence of malaria, parasite prevalence, and adverse birth outcomes.

Result

All 200 women enrolled were followed through delivery, and the primary outcome was assessed in 194. There was no statistically significant difference in the risk of histopathologically detected placental malarial infection between the daily TMP-SMX plus DP arm and the daily TMP-SMX alone arm (6.1% vs. 3.1%; relative risk, 1.96; 95% confidence interval, .50-7.61; P = .50). Similarly, there were no differences in secondary outcomes.

Conclusions

Among HIV-infected pregnant women in the setting of indoor residual spraying of insecticide, adding monthly DP to daily TMP-SMX did not reduce the risk of placental or maternal malaria or improve birth outcomes.

Clinical Trials Registration

NCT02282293.

Effect of pharmacogenetics on plasma lumefantrine pharmacokinetics and malaria treatment outcome in pregnant women

Background

Pregnancy has considerable effects on the pharmacokinetic properties of drugs used to treat uncomplicated Plasmodium falciparum malaria. The role of pharmacogenetic variation on anti-malarial drug disposition and efficacy during pregnancy is not well investigated. The study aimed to examine the effect of pharmacogenetics on lumefantrine (LF) pharmacokinetics and treatment outcome in pregnant women.

Methods

Pregnant women with uncomplicated falciparum malaria were enrolled and treated with artemether-lumefantrine (ALu) at Mkuranga and Kisarawe district hospitals in Coast Region of Tanzania. Day-7 LF plasma concentration and genotyping forCYP2B6 (c.516G>T, c.983T>C), CYP3A4*1B, CYP3A5 (*3, *6, *7) and ABCB1 c.4036A4G were determined. Blood smear for parasite quantification by microscopy, and dried blood spot for parasite screening and genotyping using qPCR and nested PCR were collected at enrolment up to day 28 to differentiate between reinfection from recrudescence. Treatment response was recorded following the WHO protocol.

Results

In total, 92 pregnant women in their second and third trimester were included in the study and 424 samples were screened for presence of P. falciparum. Parasites were detected during the follow up period in 11 (12%) women between day 7 and 28 after treatment and PCR genotyping confirmed recrudescent infection in 7 (63.3%) women. The remaining four (36.4%) pregnant women had reinfection: one on day 14 and three on day 28. The overall PCR-corrected treatment failure rate was 9.0% (95% CI 4.4–17.4). Day 7 LF concentration was not significantly influenced by CYP2B6, CYP3A4*1B and ABCB1 c.4036A>G genotypes. Significant associations between CYP3A5 genotype and day 7 plasma LF concentrations was found, being higher in carriers of CYP3A5 defective variant alleles than CYP3A5*1/*1 genotype. No significant influence of CYP2B6, CYP3A5 and ABCB1 c.4036A>Genotypes on malaria treatment outcome were observed. However, CYP3A4*1B did affect malaria treatment outcome in pregnant women followed up for 28 days (P = 0.018).

Conclusions

Genetic variations in CYP3A4 and CYP3A5may influence LF pharmacokinetics and treatment outcome in pregnant women.

Artemisinin-based combination therapy in pregnant women in Zambia: efficacy, safety and risk of recurrent malaria

Background

In Zambia, malaria is one of the leading causes of morbidity and mortality, especially among under five children and pregnant women. For the latter, the World Health Organization recommends the use of artemisinin-based combination therapy (ACT) in the second and third trimester of pregnancy. In a context of limited information on ACT, the safety and efficacy of three combinations, namely artemether–lumefantrine (AL), mefloquine–artesunate (MQAS) and dihydroartemisinin–piperaquine (DHAPQ) were assessed in pregnant women with malaria.

Methods

The trial was carried out between July 2010 and August 2013 in Nchelenge district, Luapula Province, an area of high transmission, as part of a multi-centre trial. Women in the second or third trimester of pregnancy and with malaria were recruited and randomized to one of the three study arms. Women were actively followed up for 63 days, and then at delivery and 1 year post-delivery.

Results

Nine hundred pregnant women were included, 300 per arm. PCR-adjusted treatment failure was 4.7% (12/258) (95% CI 2.7–8.0) for AL, 1.3% (3/235) (95% CI 0.4–3.7) for MQAS and 0.8% (2/236) (95% CI 0.2–3.0) for DHAPQ, with significant risk difference between AL and DHAPQ (p = 0.01) and between AL and MQAS (p = 0.03) treatments. Re-infections during follow up were more frequent in the AL (HR: 4.71; 95% CI 3.10–7.2; p < 0.01) and MQAS (HR: 1.59; 95% CI 1.02–2.46; p = 0.04) arms compared to the DHAPQ arm. PCR-adjusted treatment failure was significantly associated with women under 20 years [Hazard Ratio (HR) 5.35 (95% CI 1.07–26.73; p = 0.04)] and higher malaria parasite density [3.23 (95% CI 1.03–10.10; p = 0.04)], and still women under 20 years [1.78, (95% CI 1.26–2.52; p < 0.01)] had a significantly higher risk of re-infection. The three treatments were generally well tolerated. Dizziness, nausea, vomiting, headache and asthenia as adverse events (AEs) were more common in MQAS than in AL or DHAPQ (p < 0.001). Birth outcomes were not significantly different between treatment arms.

Conclusion

As new infections can be prevented by a long acting partner drug to the artemisinins, DHAPQ should be preferred in places as Nchelenge district where transmission is intense while in areas of low transmission intensity AL or MQAS may be used.

New developments in anti-malarial target candidate and product profiles

A decade of discovery and development of new anti-malarial medicines has led to a renewed focus on malaria elimination and eradication. Changes in the way new anti-malarial drugs are discovered and developed have led to a dramatic increase in the number and diversity of new molecules presently in pre-clinical and early clinical development. The twin challenges faced can be summarized by multi-drug resistant malaria from the Greater Mekong Sub-region, and the need to provide simplified medicines. This review lists changes in anti-malarial target candidate and target product profiles over the last 4 years. As well as new medicines to treat disease and prevent transmission, there has been increased focus on the longer term goal of finding new medicines for chemoprotection, potentially with long-acting molecules, or parenteral formulations. Other gaps in the malaria armamentarium, such as drugs to treat severe malaria and endectocides (that kill mosquitoes which feed on people who have taken the drug), are defined here. Ultimately the elimination of malaria requires medicines that are safe and well-tolerated to be used in vulnerable populations: in pregnancy, especially the first trimester, and in those suffering from malnutrition or co-infection with other pathogens. These updates reflect the maturing of an understanding of the key challenges in producing the next generation of medicines to control, eliminate and ultimately eradicate malaria.

The Safety of Artemisinin Derivatives for the Treatment of Malaria in the 2nd or 3rd Trimester of Pregnancy: A Systematic Review and Meta-Analysis

Given the high morbidity for mother and fetus associated with malaria in pregnancy, safe and efficacious drugs are needed for treatment. Artemisinin derivatives are the most effective antimalarials, but are associated with teratogenic and embryotoxic effects in animal models when used in early pregnancy. However, several organ systems are still under development later in pregnancy. We conducted a systematic review and meta-analysis of the occurrence of adverse pregnancy outcomes among women treated with artemisinins monotherapy or as artemisinin-based combination therapy during the 2nd or 3rd trimesters relative to pregnant women who received non-artemisinin antimalarials or none at all. Pooled odds ratio (POR) were calculated using Mantel-Haenszel fixed effects model with a 0.5 continuity correction for zero events. Eligible studies were identified through Medline, Embase, and the Malaria in Pregnancy Consortium Library. Twenty studies (11 cohort studies and 9 randomized controlled trials) contributed to the analysis, with 3,707 women receiving an artemisinin, 1,951 a non-artemisinin antimalarial, and 13,714 no antimalarial. The PORs (95% confidence interval (CI)) for stillbirth, fetal loss, and congenital anomalies when comparing artemisinin versus quinine were 0.49 (95% CI 0.24-0.97, I2 = 0%, 3 studies); 0.58 (95% CI 0.31-1.16, I2 = 0%, 6 studies); and 1.00 (95% CI 0.27-3.75, I2 = 0%, 3 studies), respectively. The PORs comparing artemisinin users to pregnant women who received no antimalarial were 1.13 (95% CI 0.77-1.66, I2 = 86.7%, 3 studies); 1.10 (95% CI 0.79-1.54, I2 = 0%, 4 studies); and 0.79 (95% CI 0.37-1.67, I2 = 0%, 3 studies) for miscarriage, stillbirth and congenital anomalies respectively. Treatment with artemisinin in 2nd and 3rd trimester was not associated with increased risks of congenital malformations or miscarriage and may be was associated with a reduced risk of stillbirths compared to quinine. This study updates the reviews conducted by the WHO in 2002 and 2006 and supports the current WHO malaria treatment guidelines malaria in pregnancy.

Treatment regimens for pregnant women with falciparum malaria

INTRODUCTION

With increasing parasite drug resistance, the WHO has updated treatment recommendations for falciparum malaria including in pregnancy. This review assesses the evidence for choice of treatment for pregnant women.

AREAS COVERED

Relevant studies, primarily those published since 2010, were identified from reference databases and were used to identify secondary data sources. Expert commentary: WHO recommends use of intravenous artesunate for severe malaria, quinine-clindamycin for uncomplicated malaria in first trimester, and artemisinin combination therapy for uncomplicated malaria in second/third trimesters. Because fear of adverse outcomes has often excluded pregnant women from conventional drug development, available data for novel therapies are usually based on preclinical studies and cases of inadvertent exposure. Changes in antimalarial drug disposition in pregnancy have been observed but are yet to be translated into specific treatment recommendations. Such targeted regimens may become important as parasite resistance demands that drug exposure is optimized.

Malaria prevalence, severity and treatment outcome in relation to day 7 lumefantrine plasma concentration in pregnant women

Background

Day 7 plasma concentrations of lumefantrine (LF) can serve as a marker to predict malaria treatment outcome in different study populations. Two main cut-off points (175 and 280 ng/ml) are used to indicate plasma concentrations of LF, below which treatment failure is anticipated. However, there is limited data on the cumulative risk of recurrent parasitaemia (RP) in relation to day 7 LF plasma concentrations in pregnant women. This study describes the prevalence, severity, factors influencing treatment outcome of malaria in pregnancy and day 7 LF plasma concentration therapeutic cut-off points that predicts treatment outcome in pregnant women.

Methods

This was a one-arm prospective cohort study whereby 89 pregnant women with uncomplicated Plasmodium falciparum malaria receiving artemether-lumefantrine (ALu) participated in pharmacokinetics and pharmacodynamics study. Blood samples were collected on days 0, 2, 7, 14, 21 and 28 for malaria parasite quantification. LF plasma concentrations were determined on day 7. The primary outcome measure was an adequate clinical and parasitological response (ACPR) after treatment with ALu.

Results

The prevalence of malaria in pregnant women was 8.1 % (95 % CI 6.85–9.35) of whom 3.4 % (95 % CI 1.49–8.51) had severe malaria. The overall PCR-uncorrected treatment failure rate was 11.7 % (95 % CI 0.54–13.46 %). Low baseline hemoglobin (<10 g/dl) and day 7 LF concentration <600 ng/ml were significant predictors of RP. The median day 7 LF concentration was significantly lower in pregnant women with RP (270 ng/ml) than those with ACPR (705 ng/ml) (p = 0.016). The relative risk of RP was 4.8 folds higher (p = 0.034) when cut-off of <280 ng/ml was compared to ≥280 ng/ml and 7.8-folds higher (p = 0.022) when cut-off of <600 ng/ml was compared to ≥600 ng/ml. The cut-off value of 175 ng/ml was not associated with the risk of RP (p = 0.399).

Conclusions

Pregnant women with day 7 LF concentration <600 ng/ml are at high risk of RP than those with ≥600 ng/ml. To achieve effective therapeutic outcome, higher day 7 venous plasma LF concentration ≥600 ng/ml is required for pregnant patients than the previously suggested cut-off value of 175 or 280 ng/ml for non-pregnant adult patients.

Abundance of megalin and Dab2 is reduced in syncytiotrophoblast during placental malaria, which may contribute to low birth weight

Placental malaria caused by Plasmodium falciparum contributes to ~200,000 child deaths annually, mainly due to low birth weight (LBW). Parasitized erythrocyte sequestration and consequent inflammation in the placenta are common attributes of placental malaria. The precise molecular details of placental changes leading to LBW are still poorly understood. We hypothesized that placental malaria may disturb maternofetal exchange of vitamins, lipids, and hormones mediated by the multi-ligand (n ~ 50) scavenging/signaling receptor megalin, which is abundantly expressed in placenta but was not previously analyzed in pregnancy outcomes. We studied abundance of megalin and its intracellular adaptor protein Dab2 by immunofluorescence microscopy in placental biopsies from Ugandan women with (n = 8) and without (n = 20) active placental malaria. We found that: (a) abundances of both megalin (p = 0.01) and Dab2 (p = 0.006) were significantly reduced in brush border of syncytiotrophoblast of infected placentas; (b) amounts of megalin and Dab2 were strongly correlated (Spearman's r = 0.53, p = 0.003); (c) abundances of megalin and Dab2 (p = 0.046) were reduced in infected placentas from women with LBW deliveries. This study provides first evidence that placental malaria infection is associated with reduced abundance of megalin transport/signaling system and indicate that these changes may contribute to the pathology of LBW.

Dihydroartemisinin-Piperaquine for the Prevention of Malaria in Pregnancy

BACKGROUND

Intermittent treatment with sulfadoxine-pyrimethamine is widely recommended for the prevention of malaria in pregnant women in Africa. However, with the spread of resistance to sulfadoxine-pyrimethamine, new interventions are needed.

METHODS

We conducted a double-blind, randomized, controlled trial involving 300 human immunodeficiency virus (HIV)-uninfected pregnant adolescents or women in Uganda, where sulfadoxine-pyrimethamine resistance is widespread. We randomly assigned participants to a sulfadoxine-pyrimethamine regimen (106 participants), a three-dose dihydroartemisinin-piperaquine regimen (94 participants), or a monthly dihydroartemisinin-piperaquine regimen (100 participants). The primary outcome was the prevalence of histopathologically confirmed placental malaria.

RESULTS

The prevalence of histopathologically confirmed placental malaria was significantly higher in the sulfadoxine-pyrimethamine group (50.0%) than in the three-dose dihydroartemisinin-piperaquine group (34.1%, P=0.03) or the monthly dihydroartemisinin-piperaquine group (27.1%, P=0.001). The prevalence of a composite adverse birth outcome was lower in the monthly dihydroartemisinin-piperaquine group (9.2%) than in the sulfadoxine-pyrimethamine group (18.6%, P=0.05) or the three-dose dihydroartemisinin-piperaquine group (21.3%, P=0.02). During pregnancy, the incidence of symptomatic malaria was significantly higher in the sulfadoxine-pyrimethamine group (41 episodes over 43.0 person-years at risk) than in the three-dose dihydroartemisinin-piperaquine group (12 episodes over 38.2 person-years at risk, P=0.001) or the monthly dihydroartemisinin-piperaquine group (0 episodes over 42.3 person-years at risk, P<0.001), as was the prevalence of parasitemia (40.5% in the sulfadoxine-pyrimethamine group vs. 16.6% in the three-dose dihydroartemisinin-piperaquine group [P<0.001] and 5.2% in the monthly dihydroartemisinin-piperaquine group [P<0.001]). In each treatment group, the risk of vomiting after administration of any dose of the study agents was less than 0.4%, and there were no significant differences among the groups in the risk of adverse events.

CONCLUSIONS

The burden of malaria in pregnancy was significantly lower among adolescent girls or women who received intermittent preventive treatment with dihydroartemisinin-piperaquine than among those who received sulfadoxine-pyrimethamine, and monthly treatment with dihydroartemisinin-piperaquine was superior to three-dose dihydroartemisinin-piperaquine with regard to several outcomes. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development; ClinicalTrials.gov number, NCT02163447.).

Four Artemisinin-Based Treatments in African Pregnant Women with Malaria

BACKGROUND

Information regarding the safety and efficacy of artemisinin combination treatments for malaria in pregnant women is limited, particularly among women who live in sub-Saharan Africa.

METHODS

We conducted a multicenter, randomized, open-label trial of treatments for malaria in pregnant women in four African countries. A total of 3428 pregnant women in the second or third trimester who had falciparum malaria (at any parasite density and regardless of symptoms) were treated with artemether-lumefantrine, amodiaquine-artesunate, mefloquine-artesunate, or dihydroartemisinin-piperaquine. The primary end points were the polymerase-chain-reaction (PCR)-adjusted cure rates (i.e., cure of the original infection; new infections during follow-up were not considered to be treatment failures) at day 63 and safety outcomes.

RESULTS

The PCR-adjusted cure rates in the per-protocol analysis were 94.8% in the artemether-lumefantrine group, 98.5% in the amodiaquine-artesunate group, 99.2% in the dihydroartemisinin-piperaquine group, and 96.8% in the mefloquine-artesunate group; the PCR-adjusted cure rates in the intention-to-treat analysis were 94.2%, 96.9%, 98.0%, and 95.5%, respectively. There was no significant difference among the amodiaquine-artesunate group, dihydroartemisinin-piperaquine group, and the mefloquine-artesunate group. The cure rate in the artemether-lumefantrine group was significantly lower than that in the other three groups, although the absolute difference was within the 5-percentage-point margin for equivalence. The unadjusted cure rates, used as a measure of the post-treatment prophylactic effect, were significantly lower in the artemether-lumefantrine group (52.5%) than in groups that received amodiaquine-artesunate (82.3%), dihydroartemisinin-piperaquine (86.9%), or mefloquine-artesunate (73.8%). No significant difference in the rate of serious adverse events and in birth outcomes was found among the treatment groups. Drug-related adverse events such as asthenia, poor appetite, dizziness, nausea, and vomiting occurred significantly more frequently in the mefloquine-artesunate group (50.6%) and the amodiaquine-artesunate group (48.5%) than in the dihydroartemisinin-piperaquine group (20.6%) and the artemether-lumefantrine group (11.5%) (P<0.001 for comparison among the four groups).

CONCLUSIONS

Artemether-lumefantrine was associated with the fewest adverse effects and with acceptable cure rates but provided the shortest post-treatment prophylaxis, whereas dihydroartemisinin-piperaquine had the best efficacy and an acceptable safety profile. (Funded by the European and Developing Countries Clinical Trials Partnership and others; ClinicalTrials.gov number, NCT00852423.).

The influence of pregnancy on the pharmacokinetic properties of artemisinin combination therapy (ACT): a systematic review

Background

Pregnancy has been reported to alter the pharmacokinetic properties of anti-malarial drugs, including the different components of artemisinin-based combination therapy (ACT). However, small sample sizes make it difficult to draw strong conclusions based on individual pharmacokinetic studies. The aim of this review is to summarize the evidence of the influence of pregnancy on the pharmacokinetic properties of different artemisinin-based combinations.

Methods

A PROSPERO-registered systematic review to identify clinical trials that investigated the influence of pregnancy on the pharmacokinetic properties of different forms of ACT was conducted, following PRISMA guidelines. Without language restrictions, Medline/PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, LILACS, Biosis Previews and the African Index Medicus were searched for studies published up to November 2015. The following components of ACT that are currently recommend by the World Health Organization as first-line treatment of malaria in pregnancy were reviewed: artemisinin, artesunate, dihydroartemisinin, lumefantrine, amodiaquine, mefloquine, sulfadoxine, pyrimethamine, piperaquine, atovaquone and proguanil.

Results

The literature search identified 121 reports, 27 original studies were included. 829 pregnant women were included in the analysis. Comparison of the available studies showed lower maximum concentrations (C_max) and exposure (AUC) of dihydroartemisinin, the active metabolite of all artemisinin derivatives, after oral administration of artemether, artesunate and dihydroartemisinin in pregnant women. Low day 7 concentrations were commonly seen in lumefantrine studies, indicating a low exposure and possibly reduced efficacy. The influence of pregnancy on amodiaquine and piperaquine seemed not to be clinically relevant. Sulfadoxine plasma concentration was significantly reduced and clearance rates were higher in pregnancy, while pyrimethamine and mefloquine need more research as no general conclusion can be drawn based on the available evidence. For atovaquone, the available data showed a lower maximum concentration and exposure. Finally, the maximum concentration of cycloguanil, the active metabolite of proguanil, was significantly lower, possibly compromising the efficacy.

Conclusion

These findings suggest that reassessment of the dose of the artemisinin derivate and some components of ACT are necessary to ensure the highest possible efficacy of malaria treatment in pregnant women. However, for most components of ACT, data were insufficient and extensive research with larger sample sizes will be necessary to identify the exact influences of pregnancy on the pharmacokinetic properties of different artemisinin-based combinations. In addition, different clinical studies used diverse study designs with various reported relevant outcomes. Future pharmacokinetic studies could benefit from more uniform designs, in order to increase quality, robustness and effectiveness.

Study registration: CRD42015023756 (PROSPERO)

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-016-1160-6) contains supplementary material, which is available to authorized users.

Timing of malaria in pregnancy and impact on infant growth and morbidity: a cohort study in Uganda

Background

Malaria in pregnancy (MiP) is a major cause of fetal growth restriction and low birth weight in endemic areas of sub-Saharan Africa. Understanding of the impact of MiP on infant growth and infant risk of malaria or morbidity is poorly characterized. The objective of this study was to describe the impact of MIP on subsequent infant growth, malaria and morbidity.

Methods

Between 2006 and 2009, 82 % (832/1018) of pregnant women with live-born singletons and ultrasound determined gestational age were enrolled in a prospective cohort with active weekly screening and treatment for malaria. Infants were followed monthly for growth and morbidity and received active monthly screening and treatment for malaria during their first year of life. Multivariate analyses were performed to analyse the association between malaria exposure during pregnancy and infants’ growth, malaria infections, diarrhoea episodes and acute respiratory infections.

Results

Median time of infant follow-up was 12 months and infants born to a mother who had MiP were at increased risk of impaired height and weight gain (−2.71 cm, 95 % CI −4.17 to −1.25 and −0.42 kg, 95 % CI −0.76 to −0.08 at 12 months for >1 MiP compared to no MiP) and of malaria infection (relative risk 10.42, 95 % CI 2.64–41.10 for infants born to mothers with placental malaria). The risks of infant growth restriction and infant malaria infection were maximal when maternal malaria occurred in the 12 weeks prior to delivery. Recurrent MiP was also associated with acute respiratory infection (RR 1.96, 95 % CI 1.25–3.06) and diarrhoea during infancy (RR 1.93, 95 % CI 1.02–3.66).

Conclusion

This study shows that despite frequent active screening and prompt treatment of MiP, impaired growth and an increased risk of malaria and non-malaria infections can be observed in the infants. Effective preventive measures in pregnancy remain a research priority.

This study was registered with ClinicalTrials.gov, number NCT00495508.

Artemether-Lumefantrine Pharmacokinetics and Clinical Response Are Minimally Altered in Pregnant Ugandan Women Treated for Uncomplicated Falciparum Malaria

Artemether-lumefantrine is a first-line regimen for the treatment of uncomplicated malaria during the second and third trimesters of pregnancy. Previous studies have reported changes in the pharmacokinetics and clinical outcomes following treatment with artemether-lumefantrine in pregnant women compared to nonpregnant adults; however, the results are inconclusive. We conducted a study in rural Uganda to compare the pharmacokinetics of artemether-lumefantrine and the treatment responses between 30 pregnant women and 30 nonpregnant adults with uncomplicated Plasmodium falciparum malaria. All participants were uninfected with HIV, treated with a six-dose regimen of artemether-lumefantrine, and monitored clinically for 42 days. The pharmacokinetics of artemether, its metabolite dihydroartemisinin, and lumefantrine were evaluated for 21 days following treatment. We found no significant differences in the overall pharmacokinetics of artemether, dihydroartemisinin, or lumefantrine in a direct comparison of pregnant women to nonpregnant adults, except for a statistically significant but small difference in the terminal elimination half-lives of both dihydroartemisinin and lumefantrine. There were seven PCR-confirmed reinfections (5 pregnant and 2 nonpregnant participants). The observation of a shorter terminal half-life for lumefantrine may have contributed to a higher frequency of reinfection or a shorter posttreatment prophylactic period in pregnant women than in nonpregnant adults. While the comparable overall pharmacokinetic exposure is reassuring, studies are needed to further optimize antimalarial efficacy in pregnant women, particularly in high-transmission settings and because of emerging drug resistance. (This study is registered at ClinicalTrials.gov under registration no. NCT01717885.)

Risks of miscarriage and inadvertent exposure to artemisinin derivatives in the first trimester of pregnancy: a prospective cohort study in western Kenya

BACKGROUND

The artemisinin anti-malarials are widely deployed as artemisinin-based combination therapy (ACT). However, they are not recommended for uncomplicated malaria during the first trimester because safety data from humans are scarce.

METHODS

This was a prospective cohort study of women of child-bearing age carried out in 2011-2013, evaluating the relationship between inadvertent ACT exposure during first trimester and miscarriage. Community-based surveillance was used to identify 1134 early pregnancies. Cox proportional hazard models with left truncation were used.

RESULTS

The risk of miscarriage among pregnancies exposed to ACT (confirmed + unconfirmed) in the first trimester, or during the embryo-sensitive period (≥6 to <13 weeks gestation) was higher than among pregnancies unexposed to anti-malarials in the first trimester: hazard ratio (HR) = 1.70, 95 % CI (1.08-2.68) and HR = 1.61 (0.96-2.70). For confirmed ACT-exposures (primary analysis) the corresponding values were: HR = 1.24 (0.56-2.74) and HR = 0.73 (0.19-2.82) relative to unexposed women, and HR = 0.99 (0.12-8.33) and HR = 0.32 (0.03-3.61) relative to quinine exposure, but the numbers of quinine exposures were very small.

CONCLUSION

ACT exposure in early pregnancy was more common than quinine exposure. Confirmed inadvertent artemisinin exposure during the potential embryo-sensitive period was not associated with increased risk of miscarriage. Confirmatory studies are needed to rule out a smaller than three-fold increase in risk.

Artemisinin-Based Combination Therapy Versus Quinine or Other Combinations for Treatment of Uncomplicated Plasmodium falciparum Malaria in the Second and Third Trimester of Pregnancy: A Systematic Review and Meta-Analysis

The World Health Organization recommends artemisinin-based combination therapies (ACTs) for the treatment of uncomplicated falciparum malaria in the second and third trimesters of pregnancy. We conducted a meta-analysis to compare efficacy, safety and tolerability of ACTs versus quinine and other non-ACT antimalarials. The median PCR-adjusted failure rate by days 28 to 63 in the non-ACT group was 6 (range 0–37) per 100 women, lower in the ACT group overall (pooled risk ratio [PRR] random effects, 0.41; 95% confidence interval [CI], 0.16–1.05; 6 trials), and significantly lower compared with oral quinine (PRR, 0.20; 95% CI, 0.08–0.49; 4 trials). There were no differences in fetal deaths and congenital abnormalities. Compared with quinine, artemisinin-based combinations therapies were associated with less tinnitus (PRR, 0.19; 95% CI, 0.03–1.11; 4 studies), dizziness (PRR, 0.64; 95% CI, 0.44–0.93; 3 trials), and vomiting (PRR, 0.33; 95% CI, 0.15–0.73; 3 trials). Artemisinin-based combination therapies are better than quinine in the second and third trimesters; their use should be encouraged among health workers.

Treating severe malaria in pregnancy: a review of the evidence

Severe malaria in pregnancy is a large contributor to maternal morbidity and mortality. Intravenous quinine has traditionally been the treatment drug of choice for severe malaria in pregnancy. However, recent randomized clinical trials (RCTs) indicate that intravenous artesunate is more efficacious for treating severe malaria, resulting in changes to the World Health Organization (WHO) treatment guidelines. Artemisinins, including artesunate, are embryo-lethal in animal studies and there is limited experience with their use in the first trimester. This review summarizes the current literature supporting 2010 WHO treatment guidelines for severe malaria in pregnancy and the efficacy, pharmacokinetics, and adverse event data for currently used antimalarials available for severe malaria in pregnancy. We identified ten studies on the treatment of severe malaria in pregnancy that reported clinical outcomes. In two studies comparing intravenous quinine with intravenous artesunate, intravenous artesunate was more efficacious and safe for use in pregnant women. No studies detected an increased risk of miscarriage, stillbirth, or congenital anomalies associated with first trimester exposure to artesunate. Although the WHO recommends using either quinine or artesunate for the treatment of severe malaria in first trimester pregnancies, our findings suggest that artesunate should be the preferred treatment option for severe malaria in all trimesters.

WorldWide Antimalarial Resistance Network (WWARN) Lumefantrine PK/PD Study Group. Artemether-lumefantrine treatment of uncomplicated Plasmodium falciparum malaria: a systematic review and meta-analysis of day 7 lumefantrine concentrations and therapeutic response using individual patient data

BACKGROUND

Achieving adequate antimalarial drug exposure is essential for curing malaria. Day 7 blood or plasma lumefantrine concentrations provide a simple measure of drug exposure that correlates well with artemether-lumefantrine efficacy. However, the 'therapeutic' day 7 lumefantrine concentration threshold needs to be defined better, particularly for important patient and parasite sub-populations.

METHODS

The WorldWide Antimalarial Resistance Network (WWARN) conducted a large pooled analysis of individual pharmacokinetic-pharmacodynamic data from patients treated with artemether-lumefantrine for uncomplicated Plasmodium falciparum malaria, to define therapeutic day 7 lumefantrine concentrations and identify patient factors that substantially alter these concentrations. A systematic review of PubMed, Embase, Google Scholar, ClinicalTrials.gov and conference proceedings identified all relevant studies. Risk of bias in individual studies was evaluated based on study design, methodology and missing data.

RESULTS

Of 31 studies identified through a systematic review, 26 studies were shared with WWARN and 21 studies with 2,787 patients were included. Recrudescence was associated with low day 7 lumefantrine concentrations (HR 1.59 (95% CI 1.36 to 1.85) per halving of day 7 concentrations) and high baseline parasitemia (HR 1.87 (95% CI 1.22 to 2.87) per 10-fold increase). Adjusted for mg/kg dose, day 7 concentrations were lowest in very young children (<3 years), among whom underweight-for-age children had 23% (95% CI -1 to 41%) lower concentrations than adequately nourished children of the same age and 53% (95% CI 37 to 65%) lower concentrations than adults. Day 7 lumefantrine concentrations were 44% (95% CI 38 to 49%) lower following unsupervised treatment. The highest risk of recrudescence was observed in areas of emerging artemisinin resistance and very low transmission intensity. For all other populations studied, day 7 concentrations ≥200 ng/ml were associated with >98% cure rates (if parasitemia <135,000/μL).

CONCLUSIONS

Current artemether-lumefantrine dosing recommendations achieve day 7 lumefantrine concentrations ≥200 ng/ml and high cure rates in most uncomplicated malaria patients. Three groups are at increased risk of treatment failure: very young children (particularly those underweight-for-age); patients with high parasitemias; and patients in very low transmission intensity areas with emerging parasite resistance. In these groups, adherence and treatment response should be monitored closely. Higher, more frequent, or prolonged dosage regimens should now be evaluated in very young children, particularly if malnourished, and in patients with hyperparasitemia.

Lumefantrine and Desbutyl-Lumefantrine Population Pharmacokinetic-Pharmacodynamic Relationships in Pregnant Women with Uncomplicated Plasmodium falciparum Malaria on the Thailand-Myanmar Border

Artemether-lumefantrine is the most widely used antimalarial artemisinin-based combination treatment. Recent studies have suggested that day 7 plasma concentrations of the potent metabolite desbutyl-lumefantrine correlate better with treatment outcomes than those of lumefantrine. Low cure rates have been reported in pregnant women with uncomplicated falciparum malaria treated with artemether-lumefantrine in northwest Thailand. A simultaneous pharmacokinetic drug-metabolite model was developed based on dense venous and sparse capillary lumefantrine and desbutyl-lumefantrine plasma samples from 116 pregnant patients on the Thailand-Myanmar border. The best model was used to evaluate therapeutic outcomes with a time-to-event approach. Lumefantrine and desbutyl-lumefantrine concentrations, implemented in an Emax model, both predicted treatment outcomes, but lumefantrine provided better predictive power. A combined model including both lumefantrine and desbutyl-lumefantrine did not improve the model further. Simulations suggested that cure rates in pregnant women with falciparum malaria could be increased by prolonging the treatment course. (These trials were registered at controlled-trials.com [ISRCTN 86353884].).

The emerging threat of artemisinin resistance in malaria: focus on artemether-lumefantrine

The development of artemisinin resistance in the Greater Mekong Subregion poses a significant threat to malaria elimination. Artemisinin-based combination therapies including artemether-lumefantrine (AL) are recommended by WHO as first-line treatment for uncomplicated Plasmodium falciparum malaria. This article provides a comprehensive review of the existing and latest data as a basis for interpretation of observed variability in parasite sensitivity to AL over the last 5 years. Clinical efficacy and preclinical data from a range of endemic countries are summarized, including potential molecular markers of resistance. Overall, AL remains effective in the treatment of uncomplicated P. falciparum malaria in most regions. Establishing validated molecular markers for resistance and strict efficacy monitoring will reinforce timely updates of treatment policies.

Quinine for muscle cramps

BACKGROUND

Muscle cramps can occur anywhere and for many reasons. Quinine has been used to treat cramps of all causes. However, controversy continues about its efficacy and safety. This review was first published in 2010 and searches were updated in 2014.

OBJECTIVES

To assess the efficacy and safety of quinine-based agents in treating muscle cramps.

SEARCH METHODS

On 27 October 2014 we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE and EMBASE. We searched reference lists of articles up to 2014. We also searched for ongoing trials in November 2014.

SELECTION CRITERIA

Randomised controlled trials of people of all ages with muscle cramps in any location and of any cause, treated with quinine or its derivatives.

DATA COLLECTION AND ANALYSIS

Three review authors independently selected trials for inclusion, assessed risk of bias and extracted data. We contacted study authors for additional information. For comparisons including more than one trial, we assessed the quality of the evidence using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

MAIN RESULTS

We identified 23 trials with a total of 1586 participants. Fifty-eight per cent of these participants were from five unpublished studies. Quinine was compared to placebo (20 trials, n = 1140), vitamin E (four trials, n = 543), a quinine-vitamin E combination (three trials, n = 510), a quinine-theophylline combination (one trial, n = 77), and xylocaine injections into the gastrocnemius muscle (one trial, n = 24). The most commonly used quinine dosage was 300 mg/day (range 200 to 500 mg). We found no new trials for inclusion when searches were updated in 2014.The risk of bias in the trials varied considerably. All 23 trials claimed to be randomised, but only a minority described randomisation and allocation concealment adequately.Compared to placebo, quinine significantly reduced cramp number over two weeks by 28%, cramp intensity by 10%, and cramp days by 20%. Cramp duration was not significantly affected.A significantly greater number of people suffered minor adverse events on quinine than placebo (risk difference (RD) 3%, 95% confidence interval (CI) 0% to 6%), mainly gastrointestinal symptoms. Overdoses of quinine have been reported elsewhere to cause potentially fatal adverse effects, but in the included trials there was no significant difference in major adverse events compared with placebo (RD 0%, 95% CI -1% to 2%). One participant suffered from thrombocytopenia (0.12% risk) on quinine.A quinine-vitamin E combination, vitamin E alone, and xylocaine injections into gastrocnemius were not significantly different to quinine across all outcomes, including adverse effects. Based on a single trial comparison, quinine alone was significantly less effective than a quinine-theophylline combination but with no significant differences in adverse events.

AUTHORS' CONCLUSIONS

There is low quality evidence that quinine (200 mg to 500 mg daily) significantly reduces cramp number and cramp days and moderate quality evidence that quinine reduces cramp intensity. There is moderate quality evidence that with use up to 60 days, the incidence of serious adverse events is not significantly greater than for placebo in the identified trials, but because serious adverse events can be rarely fatal, in some countries prescription of quinine is severely restricted.Evidence from single trials suggests that theophylline combined with quinine improves cramps more than quinine alone, and the effects of xylocaine injections into gastrocnemius are not significantly different to quinine across all outcomes. Low or moderate quality evidence shows no significant difference between quinine and vitamin E or quinine and quinine-vitamin E mixture. Further research into these alternatives, as well other pharmacological and non-pharmacological treatments, is thus warranted.There is no evidence to judge optimal dosage or duration of quinine treatment. Further studies using different dosages and measurement of serum quinine levels will allow a therapeutic range to be defined for muscle cramp. Because serious adverse events are not common, large population studies are required to more accurately inform incidence. Longer lengths of follow-up in future trials will help determine the duration of action following cessation of quinine as well as long-term adverse events. The search for new therapies, pharmacological and nonpharmacological, should continue and further trials should compare vitamin E, quinine-vitamin E combination, and quinine-theophylline mixture with quinine.