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Li G, Yuan Y, Zheng S, Lu C, Li M, Tan R, Zhang H, Silai R, Liu R, Said K, Bacar A, Xu Q, Song J, Wu W, Deng C. Artemisinin-Piperaquine versus Artemether-Lumefantrine for treatment of uncomplicated Plasmodium falciparum malaria in Grande Comore Island: an open-label, non-randomized controlled trial. Int J Antimicrob Agents 2022; 60:106658. [PMID: 35988664 DOI: 10.1016/j.ijantimicag.2022.106658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/28/2022] [Accepted: 08/11/2022] [Indexed: 11/05/2022]
Abstract
BACKGROUND . Malaria has rebounded significantly in 2018 in the Comoros. It posed an urgent need to conduct clinical trials to investigate the effectiveness of artemisinin and its derivatives there. METHODS . From June 2019 and January 2020, an open-label, non-randomized controlled trial of artemisinin-piperaquine (AP) and artemether-lumefantrine (AL) were conducted in Grande Comore Island. 238 uncomplicated falciparum malaria cases were enrolled and divided 1:1 into two treatments. The primary endpoint was the 42-day adequate clinical and parasitological responses (ACPR). Parasitemia and fever clearance at day 3, gametocyte, and tolerability were secondary endpoints. RESULTS . The 42-day ACPR before and after PCR-corrected were 91.43% [95% confidence interval (CI): 83.93%-95.76%] and 98.06% [95%CI: 92.48%-99.66%] for AP treatment, respectively, and 96.00% [95%CI: 88.17%-98.14%] and 98.97% [95%CI: 93.58%-99.95%] for AL treatment, respectively. Complete clearance of the parasitemia as well as of fever for both groups was detected on day 3. Gametocytes disappeared on day 21 in the AP group and on day 2 in AL group, respectively. Specifically, the adverse reactions were mild in both groups. CONCLUSIONS We discovered that AP and AL maintained their high efficacy and tolerance in the Comoros. Nonetheless, asymptomatic malaria infections bring new challenges to malaria control.
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Affiliation(s)
- Guoming Li
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, People's Republic of China
| | - Yueming Yuan
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, People's Republic of China; Institution of Science and Technology Park, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Shaoqin Zheng
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, People's Republic of China; Institution of Science and Technology Park, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Chenguang Lu
- Zhang Zhongjing School of Chinese Medicine, Nanyang Institute of Technology, Nanyang, People's Republic of China
| | - Mingqiang Li
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, People's Republic of China
| | - Ruixiang Tan
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, People's Republic of China
| | - Hongying Zhang
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, People's Republic of China
| | - Rahamatou Silai
- National Malaria Center of the Union of Comoros, Moroni, Grande Comore, The Union of Comoros
| | - Ruimei Liu
- Institution of Science and Technology Park, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Kamal Said
- National Malaria Center of the Union of Comoros, Moroni, Grande Comore, The Union of Comoros
| | - Affane Bacar
- National Malaria Center of the Union of Comoros, Moroni, Grande Comore, The Union of Comoros
| | - Qin Xu
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, People's Republic of China; The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Jianping Song
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, People's Republic of China; The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Wanting Wu
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, People's Republic of China.
| | - Changsheng Deng
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, People's Republic of China; The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China.
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A Whole-Body Physiologically Based Pharmacokinetic Model Characterizing Interplay of OCTs and MATEs in Intestine, Liver and Kidney to Predict Drug-Drug Interactions of Metformin with Perpetrators. Pharmaceutics 2021; 13:pharmaceutics13050698. [PMID: 34064886 PMCID: PMC8151202 DOI: 10.3390/pharmaceutics13050698] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 04/30/2021] [Accepted: 05/07/2021] [Indexed: 12/27/2022] Open
Abstract
Transmembrane transport of metformin is highly controlled by transporters including organic cation transporters (OCTs), plasma membrane monoamine transporter (PMAT), and multidrug/toxin extrusions (MATEs). Hepatic OCT1, intestinal OCT3, renal OCT2 on tubule basolateral membrane, and MATE1/2-K on tubule apical membrane coordinately work to control metformin disposition. Drug–drug interactions (DDIs) of metformin occur when co-administrated with perpetrators via inhibiting OCTs or MATEs. We aimed to develop a whole-body physiologically based pharmacokinetic (PBPK) model characterizing interplay of OCTs and MATEs in the intestine, liver, and kidney to predict metformin DDIs with cimetidine, pyrimethamine, trimethoprim, ondansetron, rabeprazole, and verapamil. Simulations showed that co-administration of perpetrators increased plasma exposures to metformin, which were consistent with clinic observations. Sensitivity analysis demonstrated that contributions of the tested factors to metformin DDI with cimetidine are gastrointestinal transit rate > inhibition of renal OCT2 ≈ inhibition of renal MATEs > inhibition of intestinal OCT3 > intestinal pH > inhibition of hepatic OCT1. Individual contributions of transporters to metformin disposition are renal OCT2 ≈ renal MATEs > intestinal OCT3 > hepatic OCT1 > intestinal PMAT. In conclusion, DDIs of metformin with perpetrators are attributed to integrated effects of inhibitions of these transporters.
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Abstract
About one-sixth of the world's population is affected by a neglected tropical disease as defined by the World Health Organization and Center for Disease Control. Parasitic diseases comprise most of the neglected tropical disease list and they are causing enormous amounts of disability, morbidity, mortality, and healthcare costs worldwide. The burden of disease of the top five parasitic diseases has been estimated to amount to a total 23 million disability-adjusted life-years. Despite the massive health and economic impact, most drugs currently used for the treatment of parasitic diseases have been developed decades ago and insufficient novel drugs are being developed. The current review provides a compilation of the systemic and target-site pharmacokinetics of established antiparasitic drugs. Knowledge of the pharmacokinetic profile of drugs allows for the examination and possibly optimization of existing dosing schemes. Many symptoms of parasitic diseases are caused by parasites residing in different host tissues. Penetration of the antiparasitic drug into these tissues, the target site of infection, is a prerequisite for a successful treatment of the disease. Therefore, for the examination and improvement of established dosing regimens, not only the plasma but also the tissue pharmacokinetics of the drug have to be considered. For the current paper, almost 7000 scientific articles were identified and screened from which 429 were reviewed in detail and 100 were included in this paper. Systemic pharmacokinetics are available for most antiparasitic drugs but in many cases, not for all the relevant patient populations and only for single- or multiple-dose administration. Systemic pharmacokinetic data in patients with organ impairment and target-site pharmacokinetic data for relevant tissues and body fluids are mostly lacking. To improve the treatment of patients with parasitic diseases, research in these areas is urgently needed.
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Affiliation(s)
- Valentin Al Jalali
- Department of Clinical Pharmacology, Vienna University Hospital, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
| | - Markus Zeitlinger
- Department of Clinical Pharmacology, Vienna University Hospital, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.
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Nishiyama K, Toshimoto K, Lee W, Ishiguro N, Bister B, Sugiyama Y. Physiologically-Based Pharmacokinetic Modeling Analysis for Quantitative Prediction of Renal Transporter-Mediated Interactions Between Metformin and Cimetidine. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2019; 8:396-406. [PMID: 30821133 PMCID: PMC6617824 DOI: 10.1002/psp4.12398] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 02/06/2019] [Indexed: 12/24/2022]
Abstract
Metformin is an important antidiabetic drug and often used as a probe for drug–drug interactions (DDIs) mediated by renal transporters. Despite evidence supporting the inhibition of multidrug and toxin extrusion proteins as the likely DDI mechanism, the previously reported physiologically‐based pharmacokinetic (PBPK) model required the substantial lowering of the inhibition constant values of cimetidine for multidrug and toxin extrusion proteins from those obtained in vitro to capture the clinical DDI data between metformin and cimetidine.1 We constructed new PBPK models in which the transporter‐mediated uptake of metformin is driven by a constant membrane potential. Our models successfully captured the clinical DDI data using in vitro inhibition constant values and supported the inhibition of multidrug and toxin extrusion proteins by cimetidine as the DDI mechanism upon sensitivity analysis and data fitting. Our refined PBPK models may facilitate prediction approaches for DDI involving metformin using in vitro inhibition constant values.
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Affiliation(s)
- Kotaro Nishiyama
- Pharmacokinetics and Non-Clinical Safety Department, Nippon Boehringer Ingelheim Co., Ltd., Kobe, Hyogo, Japan
| | - Kota Toshimoto
- Sugiyama Laboratory, RIKEN Baton Zone Program, RIKEN Cluster for Science, Technology and Innovation Hub, Yokohama, Kanagawa, Japan
| | - Wooin Lee
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea
| | - Naoki Ishiguro
- Pharmacokinetics and Non-Clinical Safety Department, Nippon Boehringer Ingelheim Co., Ltd., Kobe, Hyogo, Japan
| | - Bojan Bister
- Pharmacokinetics and Non-Clinical Safety Department, Nippon Boehringer Ingelheim Co., Ltd., Kobe, Hyogo, Japan
| | - Yuichi Sugiyama
- Sugiyama Laboratory, RIKEN Baton Zone Program, RIKEN Cluster for Science, Technology and Innovation Hub, Yokohama, Kanagawa, Japan
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Sugiarto SR, Davis TME, Salman S. Pharmacokinetic considerations for use of artemisinin-based combination therapies against falciparum malaria in different ethnic populations. Expert Opin Drug Metab Toxicol 2017; 13:1115-1133. [PMID: 29027504 DOI: 10.1080/17425255.2017.1391212] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Artemisinin-based combination therapy (ACT) is used extensively as first-line treatment for uncomplicated falciparum malaria. There has been no rigorous assessment of the potential for racial/ethnic differences in the pharmacokinetic properties of ACTs that might influence their efficacy. Areas covered: A comprehensive literature search was performed that identified 72 publications in which the geographical origin of the patients could be ascertained and the key pharmacokinetic parameters maximum drug concentration (Cmax), area under the plasma concentration-time curve (AUC) and elimination half-life (t½β) were available for one or more of the five WHO-recommended ACTs (artemether-lumefantrine, artesunate-amodiaquine, artesunate-mefloquine, dihydroartemisinin-piperaquine and artesunate-sulfadoxine-pyrimethamine). Comparisons of each of the three pharmacokinetic parameters of interest were made by drug (artemisinin derivative and long half-life partner), race/ethnicity (African, Asian, Caucasian, Melanesian, South American) and patient categories based on age and pregnancy status. Expert opinion: The review identified no evidence of a clinically significant influence of race/ethnicity on the pharmacokinetic properties of the nine component drugs in the five ACTs currently recommended by WHO for first-line treatment of uncomplicated falciparum malaria. This provides reassurance for health workers in malaria-endemic regions that ACTs can be given in recommended doses with the expectation of adequate blood concentrations regardless of race/ethnicity.
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Affiliation(s)
- Sri Riyati Sugiarto
- a Medical School , University of Western Australia, Fremantle Hospital , Fremantle , Australia
| | - Timothy M E Davis
- a Medical School , University of Western Australia, Fremantle Hospital , Fremantle , Australia
| | - Sam Salman
- a Medical School , University of Western Australia, Fremantle Hospital , Fremantle , Australia
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Lee SJ, ter Kuile FO, Price RN, Luxemburger C, Nosten F. Adverse effects of mefloquine for the treatment of uncomplicated malaria in Thailand: A pooled analysis of 19, 850 individual patients. PLoS One 2017; 12:e0168780. [PMID: 28192434 PMCID: PMC5305067 DOI: 10.1371/journal.pone.0168780] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 10/17/2016] [Indexed: 01/13/2023] Open
Abstract
Mefloquine (MQ) has been used for the treatment of malaria since the mid-1980s, first as monotherapy or as fixed combination with sulfadoxine-pyrimethamine (MSP) and since the mid-1990s in combination with artesunate. There is a renewed interested in MQ as part of a triple therapy for the treatment of multi-drug resistance P. falciparum malaria. The widespread use of MQ beyond south-East Asia has been constrained by reports of poor tolerability. Here we present the side effect profile of MQ for the treatment of uncomplicated malaria on the Thai-Myanmar/Cambodia borders. In total 19,850 patients received seven different regimens containing either 15 or 24-25 mg/kg of MQ, the latter given either as a single dose, or split over two or three days. The analysis focused on (predominantly) gastrointestinal and neuropsychiatric events as compared to the new fixed dose combination of MQ plus artesunate given as equal doses of 8 mg/kg MQ per day over three days. Gastrointestinal side effects were dose-dependent and associated with the severity of malaria symptoms. Serious neuropsychiatric side effects associated with MQ use were rare: for a single 25 mg/kg dose it was 11.9 per 10,000 treatments (95% confidence interval, CI, 4-285) vs. 7.8 (3-15) for the 15 mg/kg dose. The risk with 25 mg/kg was much higher when it was given as repeat dosing in patients who had failed treatment with 15 mg/kg MQ in the preceding month; (RR 6.57 (95% CI 1.33 to 32.4), p = 0.0077). MQ was best tolerated as 15 mg/kg or as 24 mg/kg when given over three days in combination with artesunate. We conclude that the tolerance of a single dose of MQ in the treatment of uncomplicated malaria is moderate, but can be improved by administering it as a split dose over three days.
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Affiliation(s)
- Sue J. Lee
- Mahidol Oxford Research Unit, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Feiko O. ter Kuile
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Ric N. Price
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Christine Luxemburger
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - François Nosten
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
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Burger RJ, Visser BJ, Grobusch MP, van Vugt M. The influence of pregnancy on the pharmacokinetic properties of artemisinin combination therapy (ACT): a systematic review. Malar J 2016; 15:99. [PMID: 26891915 PMCID: PMC4757991 DOI: 10.1186/s12936-016-1160-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Accepted: 02/10/2016] [Indexed: 11/10/2022] Open
Abstract
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 (Cmax) 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.
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Affiliation(s)
- Renée J Burger
- Division of Internal Medicine, Department of Infectious Diseases, Academic Medical Center, Center of Tropical Medicine and Travel Medicine, University of Amsterdam, Meibergdreef 9, PO Box 22700, 1100 DE, Amsterdam, The Netherlands.
| | - Benjamin J Visser
- Division of Internal Medicine, Department of Infectious Diseases, Academic Medical Center, Center of Tropical Medicine and Travel Medicine, University of Amsterdam, Meibergdreef 9, PO Box 22700, 1100 DE, Amsterdam, The Netherlands. .,Centre de Recherches de Médicales de Lambaréné (CERMEL), Albert Schweitzer Hospital, Lambaréné, Gabon.
| | - Martin P Grobusch
- Division of Internal Medicine, Department of Infectious Diseases, Academic Medical Center, Center of Tropical Medicine and Travel Medicine, University of Amsterdam, Meibergdreef 9, PO Box 22700, 1100 DE, Amsterdam, The Netherlands. .,Centre de Recherches de Médicales de Lambaréné (CERMEL), Albert Schweitzer Hospital, Lambaréné, Gabon.
| | - Michèle van Vugt
- Division of Internal Medicine, Department of Infectious Diseases, Academic Medical Center, Center of Tropical Medicine and Travel Medicine, University of Amsterdam, Meibergdreef 9, PO Box 22700, 1100 DE, Amsterdam, The Netherlands.
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Hooft van Huijsduijnen R, Guy RK, Chibale K, Haynes RK, Peitz I, Kelter G, Phillips MA, Vennerstrom JL, Yuthavong Y, Wells TNC. Anticancer properties of distinct antimalarial drug classes. PLoS One 2013; 8:e82962. [PMID: 24391728 PMCID: PMC3877007 DOI: 10.1371/journal.pone.0082962] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 10/22/2013] [Indexed: 12/31/2022] Open
Abstract
We have tested five distinct classes of established and experimental antimalarial drugs for their anticancer potential, using a panel of 91 human cancer lines. Three classes of drugs: artemisinins, synthetic peroxides and DHFR (dihydrofolate reductase) inhibitors effected potent inhibition of proliferation with IC50s in the nM- low µM range, whereas a DHODH (dihydroorotate dehydrogenase) and a putative kinase inhibitor displayed no activity. Furthermore, significant synergies were identified with erlotinib, imatinib, cisplatin, dasatinib and vincristine. Cluster analysis of the antimalarials based on their differential inhibition of the various cancer lines clearly segregated the synthetic peroxides OZ277 and OZ439 from the artemisinin cluster that included artesunate, dihydroartemisinin and artemisone, and from the DHFR inhibitors pyrimethamine and P218 (a parasite DHFR inhibitor), emphasizing their shared mode of action. In order to further understand the basis of the selectivity of these compounds against different cancers, microarray-based gene expression data for 85 of the used cell lines were generated. For each compound, distinct sets of genes were identified whose expression significantly correlated with compound sensitivity. Several of the antimalarials tested in this study have well-established and excellent safety profiles with a plasma exposure, when conservatively used in malaria, that is well above the IC50s that we identified in this study. Given their unique mode of action and potential for unique synergies with established anticancer drugs, our results provide a strong basis to further explore the potential application of these compounds in cancer in pre-clinical or and clinical settings.
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Affiliation(s)
| | - R. Kiplin Guy
- St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Kelly Chibale
- Department of Chemistry and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch, South Africa
| | - Richard K. Haynes
- Centre of Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom, South Africa
| | | | | | - Margaret A. Phillips
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Jonathan L. Vennerstrom
- Department of Pharmaceutical Sciences, Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Yongyuth Yuthavong
- BIOTEC, National Science and Technology Development Agency, Thailand Science Park, Pathumthani, Thailand
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Pharmacokinetic properties of conventional and double-dose sulfadoxine-pyrimethamine given as intermittent preventive treatment in infancy. Antimicrob Agents Chemother 2011; 55:1693-700. [PMID: 21282434 DOI: 10.1128/aac.01075-10] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Intermittent preventive treatment in infancy (IPTi) entails routine administration of antimalarial treatment doses at specified times in at-risk infants. Sulfadoxine-pyrimethamine (SDX/PYR) is a combination that has been used as first-line IPTi. Because of limited pharmacokinetic data and suggestions that higher milligram/kilogram pediatric doses than recommended should be considered, we assessed SDX/PYR disposition, randomized to conventional (25/1.25 mg/kg of body weight) or double (50/2.5 mg/kg) dose, in 70 Papua New Guinean children aged 2 to 13 months. Blood samples were drawn at baseline, 28 days, and three time points randomly selected for each infant at 4 to 8 h or 2, 5, 7, 14, or 21 days. Plasma SDX, PYR, and N(4)-acetylsulfadoxine (NSX, the principal metabolite of SDX) were assayed by high-performance liquid chromatography (HPLC). Using population modeling incorporating hepatic maturation and cystatin C-based renal function, two-compartment models provided best fits for PYR and SDX/NSX plasma concentration profiles. The area under the plasma concentration-time curve from 0 h to infinity (AUC(0-∞)) was greater with the double dose versus the conventional dose of PYR (4,915 versus 2,844 μg/day/liter) and SDX (2,434 versus 1,460 mg/day/liter). There was a 32% reduction in SDX relative bioavailability with the double dose but no evidence of dose-dependent metabolism. Terminal elimination half-lives (15.6 days for PYR, 9.1 days for SDX) were longer than previously reported. Both doses were well tolerated without changes in hemoglobin or hepatorenal function. Five children in the conventional and three in the double-dose group developed malaria during follow-up. These data support the potential use of double-dose SDX/PYR in infancy, but further studies should examine the influence of hepatorenal maturation in very young infants.
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Hodel EM, Kabanywanyi AM, Malila A, Zanolari B, Mercier T, Beck HP, Buclin T, Olliaro P, Decosterd LA, Genton B. Residual antimalarials in malaria patients from Tanzania--implications on drug efficacy assessment and spread of parasite resistance. PLoS One 2009; 4:e8184. [PMID: 20011529 PMCID: PMC2788605 DOI: 10.1371/journal.pone.0008184] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Accepted: 11/10/2009] [Indexed: 11/18/2022] Open
Abstract
Background Repeated antimalarial treatment for febrile episodes and self-treatment are common in malaria-endemic areas. The intake of antimalarials prior to participating in an in vivo study may alter treatment outcome and affect the interpretation of both efficacy and safety outcomes. We report the findings from baseline plasma sampling of malaria patients prior to inclusion into an in vivo study in Tanzania and discuss the implications of residual concentrations of antimalarials in this setting. Methods and Findings In an in vivo study conducted in a rural area of Tanzania in 2008, baseline plasma samples from patients reporting no antimalarial intake within the last 28 days were screened for the presence of 14 antimalarials (parent drugs or metabolites) using liquid chromatography-tandem mass spectrometry. Among the 148 patients enrolled, 110 (74.3%) had at least one antimalarial in their plasma: 80 (54.1%) had lumefantrine above the lower limit of calibration (LLC = 4 ng/mL), 7 (4.7%) desbutyl-lumefantrine (4 ng/mL), 77 (52.0%) sulfadoxine (0.5 ng/mL), 15 (10.1%) pyrimethamine (0.5 ng/mL), 16 (10.8%) quinine (2.5 ng/mL) and none chloroquine (2.5 ng/mL). Conclusions The proportion of patients with detectable antimalarial drug levels prior to enrollment into the study is worrying. Indeed artemether–lumefantrine was supposed to be available only at government health facilities. Although sulfadoxine–pyrimethamine is only recommended for intermittent preventive treatment in pregnancy (IPTp), it was still widely used in public and private health facilities and sold in drug shops. Self-reporting of previous drug intake is unreliable and thus screening for the presence of antimalarial drug levels should be considered in future in vivo studies to allow for accurate assessment of treatment outcome. Furthermore, persisting sub-therapeutic drug levels of antimalarials in a population could promote the spread of drug resistance. The knowledge on drug pressure in a given population is important to monitor standard treatment policy implementation.
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Affiliation(s)
| | | | - Aggrey Malila
- Ifakara Health Institute, Dar es Salaam and Ifakara, Tanzania
| | - Boris Zanolari
- Division of Clinical Pharmacology, Department de Medicine, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Thomas Mercier
- Division of Clinical Pharmacology, Department de Medicine, University Hospital and University of Lausanne, Lausanne, Switzerland
| | | | - Thierry Buclin
- Division of Clinical Pharmacology, Department de Medicine, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Piero Olliaro
- UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR), Geneva, Switzerland
| | - Laurent Arthur Decosterd
- Division of Clinical Pharmacology, Department de Medicine, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Blaise Genton
- Swiss Tropical Institute, Basel, Switzerland
- Department of Ambulatory Care and Community Medicine, University of Lausanne, Lausanne, Switzerland
- * E-mail:
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Pharmacokinetic properties of sulfadoxine-pyrimethamine in pregnant women. Antimicrob Agents Chemother 2009; 53:4368-76. [PMID: 19620325 DOI: 10.1128/aac.00335-09] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To determine the pharmacokinetic disposition of sulfadoxine (SDOX) and pyrimethamine (PYR) when administered as intermittent presumptive treatment during pregnancy (IPTp) for malaria, 30 Papua New Guinean women in the second or third trimester of pregnancy and 30 age-matched nonpregnant women were given a single dose of 1,500 mg of SDOX plus 75 mg of pyrimethamine PYR. Blood was taken at baseline and 1, 2, 4, 6, 12, 18, 24, 30, 48, and 72 h and at 7, 10, 14, 28, and 42 days posttreatment in all women. Plasma samples were assayed for SDOX, N-acetylsulfadoxine (NASDOX), and PYR by high-performance liquid chromatography. Population pharmacokinetic modeling was performed using NONMEM v6.2.0. Separate user-defined mamillary models were fitted to SDOX/NASDOX and PYR. When the covariate pregnancy was applied to clearance, there was a significant improvement in the base model for both treatments. Pregnancy was associated with a significantly lower area under the concentration-time curve from 0 to infinity for SDOX (22,315 versus 33,284 mg x h/liter), NASDOX (801 versus 1,590 mg x h/liter), and PYR (72,115 versus 106,065 microg x h/liter; P < 0.001 in each case). Because lower plasma concentrations of SDOX and PYR could compromise both curative efficacy and posttreatment prophylaxis in pregnant patients, IPTp regimens incorporating higher mg/kg doses than those recommended for nonpregnant patients should be considered.
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Dzinjalamala FK, Macheso A, Kublin JG, Taylor TE, Barnes KI, Molyneux ME, Plowe CV, Smith PJ. Association between the pharmacokinetics and in vivo therapeutic efficacy of sulfadoxine-pyrimethamine in Malawian children. Antimicrob Agents Chemother 2005; 49:3601-6. [PMID: 16127028 PMCID: PMC1195435 DOI: 10.1128/aac.49.9.3601-3606.2005] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sulfadoxine-pyrimethamine (SP) has been widely used in recent years to treat acute uncomplicated Plasmodium falciparum malaria. Risk factors for SP therapeutic failure include young age, subtherapeutic SP concentrations, and resistance-conferring genetic mutations in parasite target enzymes. A substantial proportion of patients are able to clear genetically highly resistant P. falciparum genotypes. To determine whether blood SP concentrations independently affect the patient's ability to clear resistant genotypes, we compared SP pharmacokinetics of cases of adequate clinical and parasitological response (ACPR) with cases of treatment failure (TF). When patients with ACPR and TF were compared, mean values were similar for the day 3 blood pyrimethamine (205 ng/ml versus 172 ng/ml; P = 0.25) and estimated maximum sulfadoxine (79 +/- 6.52 versus 69 +/- 6.27 mug/ml; P = 0.60) concentrations, for sulfadoxine terminal-phase elimination half-lives (7.15 versus 6.41 days; P = 0.42), and for the extents of sulfadoxine absorption (areas under the concentration-time curve of 932 +/- 100 versus 888 +/- 78.9 mug day ml(-1); P = 0.72). Among patients infected with the quintuple resistant parasites, day 3 blood pyrimethamine concentrations were higher in those who cleared the infection than in those who did not (305 +/- 35.4 versus 228 +/- 21.7 ng/ml; P = 0.037). Within this subgroup, this finding remained significant after adjusting for endogenous folate levels, age, site, and resistance-conferring mutations (odds ratio: 1.011 [1.003 to 1.024]; P = 0.018). However, as a subgroup analysis, our biologically plausible observation that higher blood pyrimethamine concentrations enhance the ability of patients to clear resistant P. falciparum should be interpreted with caution and needs further validation.
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Affiliation(s)
- Fraction K Dzinjalamala
- University of Cape Town, Division of Clinical Pharmacology, K50 Old Main Building, Groote Schuur Hospital, Cape Town 7925, South Africa
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13
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Corvaisier S, Charpiat B, Mounier C, Wallon M, Leboucher G, Al Kurdi M, Chaulet JF, Peyron F. Population pharmacokinetics of pyrimethamine and sulfadoxine in children treated for congenital toxoplasmosis. Antimicrob Agents Chemother 2004; 48:3794-800. [PMID: 15388436 PMCID: PMC521916 DOI: 10.1128/aac.48.10.3794-3800.2004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The population pharmacokinetics of pyrimethamine (PYR) and sulfadoxine (SDX) for a group of 32 children with congenital toxoplasmosis was investigated by nonparametric modeling analysis. A one-compartment model was used as the structural model, and individual pharmacokinetic parameters were estimated by Bayesian modeling. PYR (1.25 mg/kg of body weight) and SDX (25 mg/kg) were administered orally every 10 days for 1 year, with adjustment of the dose to body weight every 3 months. Drug concentrations were measured by high-performance liquid chromatography. A total of 101 measurements in serum were available for both drugs. Mean absorption rate constants, volumes of distribution, elimination rate constants, and half-lives were 0.915 h(-1), 4.379 liters/kg, 0.00839 h(-1), and 5.5 days for PYR and 1.659 h(-1), 0.392 liters/kg, 0.00526 h(-1), and 6.6 days for SDX, respectively. Wide interindividual variability was observed. The estimated minimum and maximum concentrations of PYR in serum differed 8- and 25-fold among patients, respectively, and those of SDX differed 4- and 5-fold, respectively. Increases in the concentration of PYR were observed for eight children, and increases in the SDX concentration were observed for seven children. Serum PYR-SDX concentrations are unpredictable even when the dose is standardized for body weight. The concentrations of the PYR-SDX combination that are most efficacious for children have not yet been established. A model such as ours, associated with long-term follow-up, is needed to study the correlation between exposure to these two drugs and clinical outcome in children.
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Affiliation(s)
- Stéphane Corvaisier
- Department of Pharmacy, Croix-Rousse Hospital, 103 Grande Rue de la Croix-Rousse, 69317 Lyon Cedex 04, France
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Trenque T, Simon N, Villena I, Chemla C, Quereux C, Leroux B, Jaussaud R, Rémy G, Dupouy D, Millart H, Pinon JM, Urien S. Population pharmacokinetics of pyrimethamine and sulfadoxine in children with congenital toxoplasmosis. Br J Clin Pharmacol 2004; 57:735-41. [PMID: 15151519 PMCID: PMC1884514 DOI: 10.1111/j.1365-2125.2004.02077.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
AIMS To develop a population pharmacokinetic model for pyrimethamine (PYR) and sulfadoxine (SDX) in children with congenital toxoplasmosis. METHODS Children were treated with PYR (1.25 mg kg(-1)) and SDX (25 mg kg(-1)) (Fansidar) plus folinic acid (Lederfoline) 5 mg). Plasma concentrations, available from a therapeutic drug monitoring database, were determined by high-performance liquid chromatography. Population pharmacokinetic analysis was performed using a nonlinear mixed effects model. RESULTS Eighty-nine children, aged 1 week to 14 years and weighing 2.9-59 kg, were available for evaluation. Both PYR and SDX concentration-time profiles were best described by a one-compartment open model. Volume of plasma distribution (V) and clearance (CL) were significantly related to body weight (BW) using an allometric function. Typical CL and V estimates (95% confidence interval), for a child weighing 11 kg were 5.50 (5.28, 5.73) l day(-1) and 36 (33, 39) l for PYR and 0.26 (0.25, 0.27) l day(-1) and 2.1 (1.9, 2.3) l for SDX. For BW between 3.5 and 60 kg, plasma half-lives were predicted to vary from 4.0 to 5.2 days for PYR, and from 5.0 to 7.5 days for SDX. CONCLUSION This study indicated that body weight influences PYR and SDX pharmacokinetics in children. To optimize PYR/SDX combination treatment in congenital toxoplasmosis, short dosing intervals in very young low-wight children are probably appropriate.
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Affiliation(s)
- T Trenque
- Laboratoire de Pharmacologie-Toxicologie, CHU, Reims, France.
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15
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Lebrun-Vignes B. Les antimalariques: pharmacologie, pharmacocinétique et toxicité chez l'adulte. Med Mal Infect 1999. [DOI: 10.1016/s0399-077x(00)87134-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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16
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Vergani P, Ghidini A, Ceruti P, Strobelt N, Spelta A, Zapparoli B, Rescaldani R. Congenital toxoplasmosis: efficacy of maternal treatment with spiramycin alone. Am J Reprod Immunol 1998; 39:335-40. [PMID: 9602252 DOI: 10.1111/j.1600-0897.1998.tb00527.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
PROBLEM The evidence supporting an additional benefit of a combined regimen of pyrimethamine-sulfonamides compared with spiramycin alone in the secondary prevention of congenital toxoplasmosis was critically evaluated. METHOD OF STUDY We reviewed the series of cases published in the English literature on antiparasitic treatment of acute toxoplasmosis infection in pregnancy, using spiramycin until fetal infection is documented, then using cycles of spiramycin alternated with combined pyrimethamine-sulfonamide therapy. We then compared the occurrence of overt disease among infected offspring (both severe, represented by ophthalmologic or cerebral abnormalities, and mild occurrences, represented by asymptomatic intracranial calcifications and retinal scars without visual impairment) between the published case series and our consecutive series of cases treated during a 10-year period (January 1986-December 1995) with spiramycin alone. RESULTS The prevalence of fetal infection in our series was 7.8% (12/154), similar to that reported after alternated regimens (7.0%). The rate of overt disease among infected fetuses is not different after treatment with alternated regimens than after continuous antibiotic spiramycin therapy [23% (19/82) vs. 10% (1/10); relative risk, 2.3; 95% confidence interval, 0.4, 47.0]. The pharmacokinetics of the drugs used may account for this finding. CONCLUSION The treatment of acute toxoplasmosis in pregnancy with an alternated antibiotic regimen of pyrimethamine-sulfonamide is not more efficacious at preventing overt neonatal disease than treatment with continuous spiramycin alone.
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Affiliation(s)
- P Vergani
- Division of Obstetrics and Gynecology, University of Milan, Italy
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17
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Schoondermark-van de Ven EM, Melchers WJ, Galama JM, Meuwissen JH, Eskes TK. Prenatal diagnosis and treatment of congenital Toxoplasma gondii infections: an experimental study in rhesus monkeys. Eur J Obstet Gynecol Reprod Biol 1997; 74:183-8. [PMID: 9306115 DOI: 10.1016/s0301-2115(97)00119-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The efficacy of treatment in fetuses in whom congenital Toxoplasma gondii infection has ben established has been investigated using rhesus monkeys as a model for humans. A polymerase chain reaction has been developed for the detection of Toxoplasma gondii. Using this polymerase chain reaction congenital infection can be established within 2 days of receiving an amniotic fluid sample. The polymerase chain reaction has subsequently been used to monitor the effect of treatment on fetal infection. The results show that early treatment with the combination of pyrimethamine and sulfadiazine was clearly effective in reducing the number of parasites in the infected fetus. The parasite was no longer detectable in the amniotic fluid 10 to 13 days after treatment was started. Spiramycin, on the other hand, has to be administered for at least 3 weeks to achieve the same effect. Moreover, pharmacokinetic studies revealed that spiramycin does not reach the brain. Pyrimethamine and sulfadiazine are able to pass the blood-brain barrier. Pyrimethamine appears to accumulate in the brain tissue and reaches concentrations which are also effective in vitro.
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MESH Headings
- Amniotic Fluid/parasitology
- Animals
- Anti-Infective Agents/administration & dosage
- Anti-Infective Agents/therapeutic use
- DNA, Protozoan/analysis
- DNA, Protozoan/genetics
- DNA, Ribosomal/analysis
- DNA, Ribosomal/genetics
- Disease Models, Animal
- Drug Therapy, Combination
- Female
- Fetal Diseases/diagnosis
- Fetal Diseases/drug therapy
- Fetal Diseases/parasitology
- Macaca mulatta
- Polymerase Chain Reaction
- Pregnancy
- Pregnancy Complications, Parasitic/diagnosis
- Pregnancy Complications, Parasitic/drug therapy
- Prenatal Diagnosis
- Prospective Studies
- Pyrimethamine/administration & dosage
- Pyrimethamine/therapeutic use
- Sulfadiazine/administration & dosage
- Sulfadiazine/therapeutic use
- Toxoplasma/genetics
- Toxoplasma/isolation & purification
- Toxoplasmosis, Animal/congenital
- Toxoplasmosis, Animal/diagnosis
- Toxoplasmosis, Animal/drug therapy
- Toxoplasmosis, Animal/embryology
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18
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Jacobson JM, Davidian M, Rainey PM, Hafner R, Raasch RH, Luft BJ. Pyrimethamine pharmacokinetics in human immunodeficiency virus-positive patients seropositive for Toxoplasma gondii. Antimicrob Agents Chemother 1996; 40:1360-5. [PMID: 8726001 PMCID: PMC163331 DOI: 10.1128/aac.40.6.1360] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Pyrimethamine pharmacokinetics were studied in 11 human immunodeficiency virus (HIV)-positive patients who were seropositive for exposure to Toxoplasma gondii and were taking zidovudine (AIDS Clinical Trials Group Protocol 102). Pyrimethamine was administered at 50 mg daily for 3 weeks to achieve steady state, and pharmacokinetic profiles were determined after administration of the last dose. Noncompartmental and compartmental analyses were performed. Population pharmacokinetic analysis assuming a one-compartment model yielded the following estimates: area under the 24-h concentration-time curve, 42.7 +/- 12.3 micrograms.h/ml; halflife, 139 +/- 34 h; clearance, 1.28 +/- 0.41 liters/h; volume of distribution, 246 +/- 641; and absorption rate constant, 1.5 +/- 1.3 liters/h. These values are similar to those seen in subjects without HIV infection. Pyrimethamine pharmacokinetics did not differ significantly in those subjects who were intravenous drug users. Adverse effects were noted in 73% of those initially enrolled in this study, leading to discontinuation for 38%. No association was noted between pyrimethamine levels and the incidence of adverse events. No significant differences were seen in zidovudine pharmacokinetic parameters obtained from studies performed before and during treatment with pyrimethamine. In summary, pyrimethamine exhibited pharmacokinetics in HIV-infected patients that were similar to those in non-HIV-infected subjects and it did not alter the pharmacokinetics of zidovudine in these patients.
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Affiliation(s)
- J M Jacobson
- Department of Medicine, Veterans' Affairs Medical Center, Bronx, NY 10468, USA
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19
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Lokman Hakim S, Sharifah Roohi SW, Zurkurnai Y, Noor Rain A, Mansor SM, Palmer K, Navaratnam V, Mak JW. Plasmodium falciparum: increased proportion of severe resistance (RII and RIII) to chloroquine and high rate of resistance to sulfadoxine-pyrimethamine in Peninsular Malaysia after two decades. Trans R Soc Trop Med Hyg 1996; 90:294-7. [PMID: 8758083 DOI: 10.1016/s0035-9203(96)90258-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Uncomplicated falciparum malaria patients were randomly assigned to receive either 25 mg/kg chloroquine (CHL) over 3 d or a statim dose of 25 mg/kg sulfadoxine (SDX) plus 1.25 mg/kg pyrimethamine (PYR). Patients were followed up for 28 d and the parasite response graded according to World Health Organization criteria. Overall resistance to CHL was 63.3% and 47.4% to SDX/PYR. RI, RII and RIII rates were 9.1%, 42.4% and 12.1% for CHL and 10.5%, 21.1% and 15.8% for SDX/PYR, respectively. Degree and rates of resistance to CHL were significantly correlated with pre-treatment parasite density, but not those to SDX/PYR. Plasma CHL and SDX/PYR levels were within the reported ranges and were not significantly different in patients with sensitive and resistant responses.
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Affiliation(s)
- S Lokman Hakim
- Institute for Medical Research, Jalan Pahang, Kuala Lumpur, Malaysia
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20
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Schoondermark-van de Ven E, Galama J, Vree T, Camps W, Baars I, Eskes T, Meuwissen J, Melchers W. Study of treatment of congenital Toxoplasma gondii infection in rhesus monkeys with pyrimethamine and sulfadiazine. Antimicrob Agents Chemother 1995; 39:137-44. [PMID: 7695295 PMCID: PMC162499 DOI: 10.1128/aac.39.1.137] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The efficacy of the combination of pyrimethamine and sulfadiazine for the treatment of congenital Toxoplasma gondii infection in rhesus monkeys was studied. The dosage regimen for pyrimethamine and sulfadiazine was established by pharmacokinetic studies in two monkeys. Those studies showed that the distributions of both drugs followed a one-compartment model. The serum elimination half-lives were found to be 5.2 h for sulfadiazine and 44.4 h for pyrimethamine. Sulfadiazine reached a maximum concentration in serum of 58.7 micrograms/ml, whereas a maximum concentration in serum of 0.22 micrograms/ml was found for pyrimethamine. Ten monkeys were infected intravenously with T. gondii at day 90 of pregnancy, which is comparable to the second trimester of organogenetic development in humans. Treatment was administered to six monkeys, in whose fetuses infection was diagnosed antenatally. From the moment that fetal infection was proven, the monkeys were treated throughout pregnancy with 1 mg of pyrimethamine per kg of body weight per day and 50 mg of sulfadiazine per kg of body weight per day orally. The therapy was supplemented with 3.5 mg of folinic acid once a week. No toxic side effects were found with this drug regimen. The parasite was no longer detectable in the next consecutive amniotic fluid sample, taken 10 to 13 days after treatment was started. Furthermore, T. gondii was also not found in the neonate at birth. The parasite was still present at birth in three of four untreated fetuses that served as controls. Both drugs crossed the placenta very well. Concentrations in fetal serum varied from 0.05 to 0.14 micrograms/ml for pyrimethamine and from 1.0 to 5.4 micrograms/ml for sulfadiazine. In addition, pyrimethamine was found to accumulate in the brain tissue, with concentrations being three to four times higher than the corresponding concentrations in serum. Thirty percent of the sulfadiazine was found to reach the brain tissue when compared with the corresponding serum concentration. when administered early after the onset of infection, the combination of pyrimethamine and sulfadiazine was clearly effective in reducing the number of parasites in the fetus to undetectable levels.
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21
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Karbwang J, Na-Bangchang K. Clinical application of mefloquine pharmacokinetics in the treatment of P falciparum malaria. Fundam Clin Pharmacol 1994; 8:491-502. [PMID: 7721226 DOI: 10.1111/j.1472-8206.1994.tb00830.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Malaria remains a major public health problem in large areas of the world. One of the major factors responsible for the resurgence is the emergence of Plasmodium falciparum, resistant to available antimalarials. An antimalarial, mefloquine, has been considered since its introduction as a promising alternative antimalarial drug to overcome the situation of widespread multidrug resistant P falciparum. Pharmacokinetic studies of mefloquine have been investigated in several groups of subjects either as mefloquine alone or as combined regimens. The oral absorption of mefloquine is relatively rapid, reaching peak concentrations within 24 hours. Metabolism takes place in the liver, with carboxymefloquine as a major metabolite. Mefloquine has a large apparent volume of distribution of 200 L and is highly bound (98%) to plasma proteins. The elimination is slow; the terminal half-life is 13 10 to 14 days in Thai patients with falciparum malaria. Vomiting within 1 hour of drug administration has an influence on blood concentrations of mefloquine and this may result in treatment failure. The whole blood concentrations of mefloquine on the first two days of treatment are important determinants of parasitological response. There appear to be no pharmacokinetic interactions between mefloquine and the other two components of Fansimef in patients with uncomplicated falciparum malaria. The advantage of this combination over mefloquine alone in multidrug resistant P falciparum is still debatable. However, recent data seem to support the higher efficacy of Fansimef over mefloquine alone. Concurrent administration of antibiotics, ie ampicillin and tetracycline with mefloquine results in a significant increase in maximum concentration, reduction of the apparent volume of distribution and shortening of the terminal elimination half-life of mefloquine. An antiemetic drug metoclopramide accelerates the absorption of mefloquine and increases the maximum concentration. In contrast, mefloquine concentrations are decreased in the presence of an antimalarial, artesunate. Primaquine has no effect on the pharmacokinetics of mefloquine when given concurrently.
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Affiliation(s)
- J Karbwang
- Clinical Pharmacology Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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22
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Palmer KJ, Holliday SM, Brogden RN. Mefloquine. A review of its antimalarial activity, pharmacokinetic properties and therapeutic efficacy. Drugs 1993; 45:430-75. [PMID: 7682911 DOI: 10.2165/00003495-199345030-00009] [Citation(s) in RCA: 129] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Mefloquine is an orally administered blood schizontocide. Initial dose-finding and comparative studies performed between 1977 and 1989 demonstrated efficacy of mefloquine as prophylaxis in nonimmune individuals and in the suppression and treatment of malaria in adults and children caused by multidrug-resistant Plasmodium falciparum. It was also effective against P. vivax infection, while data concerning the treatment of P. ovale and P. malariae infections were limited. In an attempt to delay the emergence of resistance to this promising antimalarial agent, mefloquine was combined with sulfadoxine and pyrimethamine. Although initial clinical trials indicated that this regimen was effective in preventing and treating falciparum malaria, recent treatment failures, the potential for severe dermatological reactions and lack of therapeutic advantage over mefloquine alone has prompted the World Health Organization to recommended that the combination be no longer used for treatment or prophylaxis of malaria. Mefloquine is generally well tolerated in both adults and children, with nausea, vomiting, diarrhoea, headache, dizziness, rash, pruritus and abdominal pain being the most common adverse effects, although it is difficult to distinguish between disease- and treatment-related events. The incidence of these adverse effects is similar to or lower than those observed with other antimalarial agents. Cardiovascular changes, such as bradycardia, occasionally occur. The most notable adverse effects associated with mefloquine are neuropsychiatric disturbances; precipitation of such events should be closely monitored and requires termination of prophylaxis or therapy. The eventual emergence of resistance to mefloquine, as with many other antimalarial agents, was inevitable. Mefloquine resistance is established in certain areas of Thailand and may be becoming a growing problem in other regions of the world. In order to preserve the efficacy of mefloquine in non-resistant areas, this useful agent should be used with care and only prescribed for prophylaxis in travellers and treatment in areas of multidrug-resistant plasmodia. Future options to combat mefloquine resistance may include the combination of mefloquine with other antimalarial agents such as qinghaosu derivatives. Thus, with cautious use and possible combination with other agents, mefloquine is likely to remain an important treatment option for falciparum malaria, a widespread parasitic disease for which an increasing number of drugs have proved inadequate.
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Affiliation(s)
- K J Palmer
- Adis International Limited, Auckland, New Zealand
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23
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McLeod R, Mack D, Foss R, Boyer K, Withers S, Levin S, Hubbell J. Levels of pyrimethamine in sera and cerebrospinal and ventricular fluids from infants treated for congenital toxoplasmosis. Toxoplasmosis Study Group. Antimicrob Agents Chemother 1992; 36:1040-8. [PMID: 1510391 PMCID: PMC188832 DOI: 10.1128/aac.36.5.1040] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Pyrimethamine levels in sera, cerebrospinal fluid (CSF), and ventricular fluid were measured by using reversed-phase high-pressure liquid chromatography. The specimens were from 37 infants receiving pyrimethamine for treatment of suspect or proven congenital toxoplasmosis. Pyrimethamine half-life in serum was 64 +/- 12 h when determined by study of terminal-phase kinetics of samples obtained from nine babies. This half-life was significantly different (P = 0.008) from the pyrimethamine half-life (33 +/- 12 h) determined by terminal-phase kinetics for two babies of the same age taking phenobarbital. Serum pyrimethamine levels at various intervals after dosages of pyrimethamine were also lower for infants receiving phenobarbital. Levels measured in sera from babies taking the same dose of pyrimethamine throughout their first year of life did not appear to vary significantly over time or at different ages (P greater than 0.05). Mean +/- standard deviation serum levels 4 h after a pyrimethamine dose were 1.297 +/- 0.54 micrograms/ml for babies taking 1 mg of pyrimethamine per kg of body weight daily and 0.7 +/- 0.26 microgram/ml for babies taking 1 mg/kg each Monday, Wednesday, and Friday. Levels in CSF were approximately 10 to 25% of concomitant levels in serum. Serum folate levels for infants who took 0.64 to 1.7 mg leukovorin per kg ranged from 33 to 663 ng/ml. To determine whether the levels of pyrimethamine in serum and CSF of treated infants were in a range that affected the most virulent, rapidly replicating, and standard laboratory strain of Toxoplasma gondii, effects of various concentrations of pyrimethamine and sulfadiazine on replication of T. gondii in vitro were assessed. The levels of the antimicrobial agents effective in vitro were in the range of levels of pyrimethamine achieved in sera and CSF. Although folinic acid could inhibit the therapeutic effect of pyrimethamine and sulfadiazine in vitro, inhibition was noted only at levels (> or = 4,800 ng/ml) that were considerably higher than the folate levels found in the treated infants' sera.
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Affiliation(s)
- R McLeod
- Department of Medicine, Michael Reese Medical Center, Chicago, Illinois 60616
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Abstract
Mefloquine, a quinoline-methanol antimalarial, is effective single dose therapy for all species of malaria infecting humans, including multi-drug-resistant Plasmodium falciparum. It is used both in prophylaxis and treatment. Mefloquine is available either as the hydrochloride salt alone, or in a combined preparation with sulfadoxine and pyrimethamine. There is no parenteral formulation. Several assay methodologies have been developed, but high performance liquid chromatography has been the most used in recent pharmacokinetic studies. These have shown in healthy volunteers that mefloquine is absorbed with a half-life of 1 to 4 hours and a time to peak concentration of 7 to 24 hours (median 16.7 hours). Mean peak blood concentrations have ranged between 50 and 110 (median 83) ng/ml/mg/kg. Estimates of total apparent volume of distribution (Vd/f) have ranged from 13.3 to 40.9 (median 19.2) L/kg, systemic clearance (CL/f) from 0.022 to 0.073 L/h/kg (median 0.026 L/h/kg), and terminal elimination half-life from 13.8 to 40.9 days (median 20 days). Systemic clearance appears to be increased in late pregnancy. In uncomplicated falciparum malaria, peak blood concentrations are 2 to 3 times higher than those in healthy subjects ranging from 112 to 209 (median 144) ng/ml/mg/kg because of contraction in the total apparent volume of distribution. Systemic clearance is usually reduced but elimination rates are increased (possibly because of reduced enterohepatic recycling). Mefloquine absorption appears to be reduced in severe falciparum malaria; plasma protein binding exceeds 98% in both healthy subjects and patients. No important drug interactions have been identified as yet, but the potential for serious interactions with quinine has not been adequately investigated. More studies are needed on the disposition of mefloquine in children.
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Affiliation(s)
- J Karbwang
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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Nosten F, Karbwang J, White NJ, Honeymoon, Na Bangchang K, Bunnag D, Harinasuta T. Mefloquine antimalarial prophylaxis in pregnancy: dose finding and pharmacokinetic study. Br J Clin Pharmacol 1990; 30:79-85. [PMID: 2390434 PMCID: PMC1368278 DOI: 10.1111/j.1365-2125.1990.tb03746.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
1. A dose finding pharmacokinetic study was performed in 20 Karen women in the third trimester of pregnancy receiving antimalarial prophylaxis with mefloquine. Ten received 250 mg mefloquine base weekly and ten received identical tablets of 125 mg base/week. 2. Both dose regimens were well tolerated. Malaria was prevented effectively, there were no serious adverse effects, all pregnancies proceeded normally, and there were no abnormalities in the babies followed up to 2 years. 3. The median time from dose administration to peak whole blood mefloquine concentration was 6 (range 3-24) h. Mean (+/- s.d.) peak and trough concentrations in the seventh week were 722 +/- 279 and 488 +/- 155 ng ml-1 with the 250 mg/week dose, and 390 +/- 81 and 185 +/- 53 ng ml-1 with the 125 mg/week dose regimens respectively. These blood concentration values are lower than those reported previously in non-pregnant adults. 4. One and two compartmental models were fitted to the whole blood concentration-time data. Mean (+/- s.d.) clearance (CL/F) was 0.78 +/- 0.27 ml min-1 kg-1, and the apparent terminal elimination half-life (t1/2) was 11.6 +/- 7.9 days. 5. Further studies to determine the oral bioavailability of mefloquine are needed, but these results suggest that clearance may be increased in late pregnancy. These preliminary results of good efficacy without significant toxicity are encouraging, and a more extensive evaluation of mefloquine antimalarial prophylaxis in pregnancy is now warranted.
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Affiliation(s)
- F Nosten
- Bangkok Hospital for Tropical Diseases, Faculty of Tropical Medicine, Mahidol University, Thailand
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