Safe shortening of antibiotic treatment duration for complicated Staphylococcus aureus bacteraemia (SAFE trial): protocol for a randomised, controlled, open-label, non-inferiority trial comparing 4 and 6 weeks of antibiotic treatment

INTRODUCTION

A major knowledge gap in the treatment of complicated Staphylococcus aureus bacteraemia (SAB) is the optimal duration of antibiotic therapy. Safe shortening of antibiotic therapy has the potential to reduce adverse drug events, length of hospital stay and costs. The objective of the SAFE trial is to evaluate whether 4 weeks of antibiotic therapy is non-inferior to 6 weeks in patients with complicated SAB.

METHODS AND ANALYSIS

The SAFE-trial is a multicentre, non-inferiority, open-label, parallel group, randomised controlled trial evaluating 4 versus 6 weeks of antibiotic therapy for complicated SAB. The study is performed in 15 university hospitals and general hospitals in the Netherlands. Eligible patients are adults with methicillin-susceptible SAB with evidence of deep-seated or metastatic infection and/or predictors of complicated SAB. Only patients with a satisfactory clinical response to initial antibiotic treatment are included. Patients with infected prosthetic material or an undrained abscess of 5 cm or more at day 14 of adequate antibiotic treatment are excluded. Primary outcome is success of therapy after 180 days, a combined endpoint of survival without evidence of microbiologically confirmed disease relapse. Assuming a primary endpoint occurrence of 90% in the 6 weeks group, a non-inferiority margin of 7.5% is used. Enrolment of 396 patients in total is required to demonstrate non-inferiority of shorter antibiotic therapy with a power of 80%. Currently, 152 patients are enrolled in the study.

ETHICS AND DISSEMINATION

This is the first randomised controlled trial evaluating duration of antibiotic therapy for complicated SAB. Non-inferiority of 4 weeks of treatment would allow shortening of treatment duration in selected patients with complicated SAB. This study is approved by the Medical Ethics Committee VUmc (Amsterdam, the Netherlands) and registered under NL8347 (the Netherlands Trial Register). Results of the study will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NL8347 (the Netherlands Trial Register).

Indwelling time of peripherally inserted central catheters and incidence of bloodstream infections in haematology patients: a cohort study

Background

We aimed to assess whether longer indwelling time of peripherally inserted central catheters (PICC) increases risk of central line associated bloodstream infections (CLABSI) in haematology patients.

Methods

Multicentre retrospective cohort study among haematology patients receiving PICCs between 2013 and 2015. Occurrence of CLABSI based on CDC definitions was assessed. We calculated incidence rates, determined risk factors for CLABSI and used Poisson regression models to assess the risk of developing CLABSI as a function of PICC dwell time. We compared diagnoses and treatment characteristics between 2013–2015 and 2015–2020.

Results

455 PICCs placed in 370 patients were included, comprising 19,063 catheter days. Median indwelling time was 26 days (range 0–385) and CLABSI incidence was 4.0 per 1000 catheter days, with a median time to CLABSI of 33 days (range 18–158). Aplastic anaemia (AA) was associated with an increased risk of CLABSI; patients undergoing autologous stem cell transplantation (SCT) were less likely to develop CLABSI. In the unadjusted analysis, PICCs with an indwelling time of 15–28 days, 29–42 days, 43–56 days and > 56 days each had an increased CLABSI incidence rate ratio of 2.4 (1.2–4.8), 2.2 (0.95–5.0), 3.4 (1.6–7.5) and 1.7 (0.9–3.5), respectively, compared to PICCs in place for < 15 days. However, after adjusting for AA and SCT, there was no significant difference in incidence rates between dwell times (p 0.067).

Conclusions

Our study shows that risk of CLABSI does not appear to increase with longer PICC indwelling time. Routine replacement of PICCs therefore is unlikely to prevent CLABSI in this population.

A highly virulent variant of HIV-1 circulating in the Netherlands

We discovered a highly virulent variant of subtype-B HIV-1 in the Netherlands. One hundred nine individuals with this variant had a 0.54 to 0.74 log₁₀ increase (i.e., a ~3.5-fold to 5.5-fold increase) in viral load compared with, and exhibited CD4 cell decline twice as fast as, 6604 individuals with other subtype-B strains. Without treatment, advanced HIV-CD4 cell counts below 350 cells per cubic millimeter, with long-term clinical consequences-is expected to be reached, on average, 9 months after diagnosis for individuals in their thirties with this variant. Age, sex, suspected mode of transmission, and place of birth for the aforementioned 109 individuals were typical for HIV-positive people in the Netherlands, which suggests that the increased virulence is attributable to the viral strain. Genetic sequence analysis suggests that this variant arose in the 1990s from de novo mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence.

The potential of training specialist oncology nurses in real-life reporting of adverse drug reactions

Specialist oncology nurses (SONs) have the potential to play a major role in monitoring and reporting adverse drug reactions (ADRs); and reduce the level of underreporting by current healthcare professionals. The aim of this study was to investigate the long term clinical and educational effects of real-life pharmacovigilance education intervention for SONs on ADR reporting. This prospective cohort study, with a 2-year follow-up, was carried out in the three postgraduate schools in the Netherlands. In one of the schools, the prescribing qualification course was expanded to include a lecture on pharmacovigilance, an ADR reporting assignment, and group discussion of self-reported ADRs (intervention). The clinical value of the intervention was assessed by analyzing the quantity and quality of ADR-reports sent to the Netherlands Pharmacovigilance Center Lareb, up to 2 years after the course and by evaluating the competences regarding pharmacovigilance of SONs annually. Eighty-eight SONs (78% of all SONs with a prescribing qualification in the Netherlands) were included. During the study, 82 ADRs were reported by the intervention group and 0 by the control group. This made the intervention group 105 times more likely to report an ADR after the course than an average nurse in the Netherlands. This is the first study to show a significant and relevant increase in the number of well-documented ADR reports after a single educational intervention. The real-life pharmacovigilance educational intervention also resulted in a long-term increase in pharmacovigilance competence. We recommend implementing real-life, context- and problem-based pharmacovigilance learning assignments in all healthcare curricula.

Accelerated treatment with rtPA for pulmonary embolism induced circulatory arrest

Patients with circulatory arrest due to pulmonary embolism (PE) should be treated with fibrinolytics. Current guidelines do not specify which regimen to apply, and it has been suggested that the regimen of 100 mg rtPA/2 h should be used, because this is recommended for hemodynamic instable PE in the ESC/ERS Guideline. This two hour regimen, however, is incompatible with key principles of cardiopulmonary resuscitation (CPR), such as employment of interventions that allow fast evaluation of effectiveness, and limitation of the total duration of CPR to avoid poor neurological outcomes. Additionally, the low flow-state during CPR has important consequences for the pharmacokinetic properties of rtPA. Arguably, the volume of distribution is lower, the metabolism reduced and the half life time longer. Therefore, these changes largely discard the rationale to use high dosages of rtPA over a prolonged period of time. More importantly, these changes highlight that the guideline recommendations, based on studies in patients without circulatory arrest, cannot be easily translated to the situation of circulatory arrest. An accelerated regimen of rtPA (0.6 mg/kg/15 min., max 50 mg) is mentioned by the 2019 ESC/ERS Guideline. However, empirical support or a rationale is not provided. Due to the rarity of the situation and ethical difficulties associated with randomizing unconscious patients, a randomized head-to-head comparison between the two regimens is unlikely to ever be performed. With this comprehensive overview of the pharmacokinetics of rtPA and current literature, a strong rationale is provided that the accelerated protocol is the regimen of choice for patients with PE-induced circulatory arrest.

Medical students as adverse drug event managers, learning about side effects while improving their reporting in clinical practice

Managing adverse drug reactions (ADRs) is a challenge, especially because most healthcare professionals are insufficiently trained for this task. Since context-based clinical pharmacovigilance training has proven effective, we assessed the feasibility and effect of a creating a team of Junior-Adverse Drug Event Managers (J-ADEMs). The J-ADEM team consisted of medical students (1st–6th year) tasked with managing and reporting ADRs in hospitalized patients. Feasibility was evaluated using questionnaires. Student competence in reporting ADRs was evaluated using a case-control design and questionnaires before and after J-ADEM program participation. From Augustus 2018 to Augustus 2019, 41 students participated in a J-ADEM team and screened 136 patients and submitted 65 ADRs reports to the Netherlands Pharmacovigilance Center Lareb. Almost all patients (n = 61) found it important that “their” ADR was reported, and all (n = 62) patients felt they were taken seriously by the J-ADEM team. Although attending physicians agreed that the ADRs should have been reported, they did not do so themselves mainly because of a “lack of knowledge and attitudes” (50%) and “excuses made by healthcare professionals” (49%). J-ADEM team students were significantly more competent than control students in managing ADRs and correctly applying all steps for diagnosing ADRs (control group 38.5% vs. intervention group 83.3%, p < 0.001). The J-ADEM team is a feasible approach for detecting and managing ADRs in hospital. Patients were satisfied with the care provided, physicians were supported in their ADR reporting obligations, and students acquired relevant basic and clinical pharmacovigilance skills and knowledge, making it a win-win-win intervention.

[Which side effects should I inform patients about?]

The law requires that healthcare professionals adequately inform patients about possible side effects when they prescribe new pharmacological treatments. There are several reasons (lack of time, fear of nocebo effect, patient and prescriber preferences) why informing patients in detail could be undesirable or even harmful. Prescribers should focus on two types of side effects: (a) common side effects with significant impact on the quality of life and (b) side effects that should be recognised in time to prevent further harm. During treatment, patients should be monitored regularly for efficacy and side effects in order to weigh benefits and risks and to stop or switch therapy when necessary.

High Treatment Uptake in Human Immunodeficiency Virus/Hepatitis C Virus-Coinfected Patients After Unrestricted Access to Direct-Acting Antivirals in the Netherlands

Background

The Netherlands has provided unrestricted access to direct-acting antivirals (DAAs) since November 2015. We analyzed the nationwide hepatitis C virus (HCV) treatment uptake among patients coinfected with human immunodeficiency virus (HIV) and HCV.

Methods

Data were obtained from the ATHENA HIV observational cohort in which >98% of HIV-infected patients ever registered since 1998 are included. Patients were included if they ever had 1 positive HCV RNA result, did not have spontaneous clearance, and were known to still be in care. Treatment uptake and outcome were assessed. When patients were treated more than once, data were included from only the most recent treatment episode. Data were updated until February 2017. In addition, each treatment center was queried in April 2017 for a data update on DAA treatment and achieved sustained virological response.

Results

Of 23574 HIV-infected patients ever linked to care, 1471 HCV-coinfected patients (69% men who have sex with men, 15% persons who [formerly] injected drugs, and 15% with another HIV transmission route) fulfilled the inclusion criteria. Of these, 87% (1284 of 1471) had ever initiated HCV treatment between 2000 and 2017, 76% (1124 of 1471) had their HCV infection cured; DAA treatment results were pending in 6% (92 of 1471). Among men who have sex with men, 83% (844 of 1022) had their HCV infection cured, and DAA treatment results were pending in 6% (66 of 1022). Overall, 187 patients had never initiated treatment, DAAs had failed in 14, and a pegylated interferon-alfa-based regimen had failed in 54.

Conclusions

Fifteen months after unrestricted DAA availability the majority of HIV/HCV-coinfected patients in the Netherlands have their HCV infection cured (76%) or are awaiting DAA treatment results (6%). This rapid treatment scale-up may contribute to future HCV elimination among these patients.

Antibiotic treatment for 6 days versus 12 days in patients with severe cellulitis: a multicentre randomized, double-blind, placebo-controlled, non-inferiority trial

OBJECTIVES

To investigate whether antibiotic treatment of 6 days' duration is non-inferior to treatment for 12 days in patients hospitalized for cellulitis.

METHODS

This multicentre, randomized, double-blind, placebo-controlled, non-inferiority trial enrolled adult patients hospitalized for severe cellulitis who were treated with intravenous flucloxacillin. At day 6 participants with symptom improvement who were afebrile were randomized between an additional 6 days of oral flucloxacillin or placebo in a 1:1 ratio, stratified for diabetes and hospital. The primary outcome was cure by day 14, without relapse by day 28. Secondary outcomes included a modified cure assessment and relapse rate by day 90.

RESULTS

Between August 2014 and June 2017, 151 of 248 included participants were randomized. The intention-to-treat population consisted of 76 and 73 participants allocated to 12 and 6 days of antibiotic therapy, respectively (mean age 62 years, 67% males, 24% diabetics); 38/76 (50.0%) and 36/73 (49.3%) were cured in the 12- and 6-day groups respectively (ARR 0.7 percentage points, 95%CI: -15.0 to 16.3). Cure rates were 56/76 (73.7%) and 49/73 (67.1%) with the modified cure assessment (ARR 6.6, 95%CI: -8.0 to 20.8). After initial cure without relapse, day 90 relapse rates were higher in the 6-day group (6% versus 24%, p < 0.05).

CONCLUSIONS

Given the wide confidence intervals, we can neither confirm nor refute our hypothesis that 6 days of therapy is non-inferior to 12 days of therapy. However, a 6-day course resulted in significantly more frequent relapses by day 90. These findings require confirmation in future studies.

Urgent need to modernize pharmacovigilance education in healthcare curricula: review of the literature

OBJECTIVES

Pharmacovigilance education is essential since adverse drug reactions (ADRs) are a serious health problem and contribute to unnecessary patient burden and hospital admissions. Healthcare professionals have little awareness of pharmacovigilance and ADR reporting, and only few educational interventions had durable effects on this awareness. Our future healthcare providers should therefore acquire an adequate set of pharmacovigilance competencies to rationally prescribe, distribute, and monitor drugs. We investigated the pharmacovigilance and ADR-reporting competencies of healthcare students to identify educational interventions that are effective in promoting pharmacovigilance.

METHODS

The PubMed, EMBASE, Cochrane, CINAHL, PsycINFO, and ERIC databases were searched using the terms "pharmacovigilance," "students," and "education.".

RESULTS

Twenty-five cross-sectional and 14 intervention studies describing mostly medical and pharmacy students were included. Intentions and attitudes on ADR reporting were overall positive, although most students felt inadequately prepared, missed the training on this topic, and lacked basic knowledge. Although nearly all students observed ADRs during clinical rounds, only a few had actually been involved in reporting an ADR. Educational interventions were predominately lectures, sometimes accompanied by small interactive working groups. Most interventions resulted in a direct increase in knowledge with an unknown long-term effect. Real-life learning initiatives have shown that healthcare students are capable of contributing to patient care while increasing their ADR-reporting skills and knowledge.

CONCLUSIONS

There is an urgent need to improve and innovate current pharmacovigilance education for undergraduate healthcare students. By offering real-life pharmacovigilance training, students will increase their knowledge and awareness but can also assist current healthcare professionals to meet their pharmacovigilance obligations.

The impact of laboratory closing times on delay of adequate therapy in blood stream infections

BACKGROUND

Patients with bloodstream infections need early adequate antimicrobial treatment to reduce mortality. This raises the question of timing and logistics. How important is the time of day when a culture is flagged positive to the processing of blood cultures and optimisation of antimicrobial therapy?

METHODS

We performed a retrospective study assessing the time delay of a positive blood culture result during and after office hours and its impact on adequate antimicrobial therapy. Process duration from the moment of culture positivity to Gram stain completion was compared at different timepoints during the day in a medium-sized hospital with an offsite microbiological laboratory.

RESULTS

Ninety-four patients with positive, noncontaminated blood cultures were included. Sixty-six patients (70%) received adequate empirical therapy; this increased to 76 cases (82%) and to 88 cases (95%) after analysis of Gram stain results and complete determination, respectively (p < 0.05 for all comparisons). Median duration from culture positivity to Gram stain completion (including offsite culture transport) increased from a median of four to 12 hours if time of cultures turned positive after office hours (p < 0.05), irrespective of the adequacy of empirical coverage. This also resulted in a median 12-hour delay for the complete process from time of culture positivity to administration of the antimicrobial drug (p < 0.05).

CONCLUSION

Processing blood cultures after office hours is often deferred, which can lead to a delay in adequate antimicrobial therapy for patients with bloodstream infections.

Pharmacology and Therapeutics Education in the European Union Needs Harmonization and Modernization: A Cross-sectional Survey Among 185 Medical Schools in 27 Countries

Effective teaching in pharmacology and clinical pharmacology and therapeutics (CPT) is necessary to make medical students competent prescribers. However, the current structure, delivery, and assessment of CPT education in the European Union (EU) is unknown. We sent an online questionnaire to teachers with overall responsibility for CPT education in EU medical schools. Questions focused on undergraduate teaching and assessment of CPT, and students' preparedness for prescribing. In all, 185 medical schools (64%) from 27 EU countries responded. Traditional learning methods were mainly used. The majority of respondents did not provide students with the opportunity to practice real-life prescribing and believed that their students were not well prepared for prescribing. There is a marked difference in the quality and quantity of CPT education within and between EU countries, suggesting that there is considerable scope for improvement. A collaborative approach should be adopted to harmonize and modernize the undergraduate CPT education across the EU.

Effect of an antibiotic checklist on length of hospital stay and appropriate antibiotic use in adult patients treated with intravenous antibiotics: a stepped wedge cluster randomized trial

OBJECTIVES

Quality indicators (QIs) have been developed to define appropriate antibiotic use in hospitalized patients. We evaluated whether a checklist based on these QIs affects appropriate antibiotic use and length of hospital stay.

METHODS

An antibiotic checklist for patients treated with intravenous antibiotics was introduced in nine Dutch hospitals in a stepped wedge cluster randomized trial. Prophylaxis was excluded. We included a random sample before (baseline), and all eligible patients after (intervention) checklist introduction. Baseline and intervention outcomes were compared. Primary endpoint was length of stay (LOS), analysed by intention to treat. Secondary endpoints, including QI performances, QI sum score (performance on all QIs per patient), and quality of checklist use, were analysed per protocol.

RESULTS

Between 1 November 2014 and 1 October 2015 we included 853 baseline and 5354 intervention patients, of whom 993 (19%) had a completed checklist. The LOS did not change (baseline geometric mean 10.0 days (95% CI 8.6-11.5) versus intervention 10.1 days (95% CI 8.9-11.5), p 0.8). QI performances increased between +3.0% and +23.9% per QI, and the percentage of patients with a QI sum score above 50% increased significantly (OR 2.4 (95% CI 2.0-3.0), p<0.001). Higher QI sum scores were significantly associated with shorter LOS. Discordance existed between checklist-answers and actual performance.

CONCLUSIONS

Use of an antibiotic checklist resulted in a significant increase in appropriateness of antibiotic use, but not in a reduction of LOS. Low overall checklist completion rates and discordance between checklist-answers and actual provided care might have attenuated the impact of the checklist.

[Thiamine in patients with alcohol use disorder and Wernicke's encephalopathy]

- Patients with alcohol use disorder frequently have a thiamine deficiency.- A potential life-threatening complication of thiamine deficiency is Wernicke's encephalopathy.- Since it is clinically difficult to recognize Wernicke's encephalopathy, this condition is often treated inadequately. - Early supplementation of thiamine is important to avoid irreversible neurological damage. - There are differences between the Dutch guidelines regarding the supplementation of thiamine for the treatment of alcoholic use disorder, and those for Wernicke's encephalopathy. - There are no solid evidence-based recommendations about the best dosage, route of administration and duration of thiamine supplementation for the treatment of alcohol use disorder and Wernicke's encephalopathy. - Based on the pharmacokinetic properties of thiamine, it is more appropriate to give patients with alcohol use disorder 25 mg four times a day rather than 50 mg twice a day. - Patients at high risk of Wernicke's encephalopathy should immediately receive an intravenous or intramuscular dose of thiamine; patients with suspected Wernicke's encephalopathy should preferably receive an intravenous dose.- Reports of anaphylactic reaction to parenteral administration of thiamine are rare and are not a reason to refrain from parenteral treatment.

The prescribing performance and confidence of final-year medical students

It is widely believed that medical students are not as well prepared or as sufficiently skilled in prescribing as they should be at the outset of their careers. However, a preclinical context-learning pharmacotherapy program has been found to improve students' therapeutic skills during an ensuing clinical clerkship in internal medicine.(1) In this Commentary, we argue that a similar approach during a clinical clerkship may further enhance therapeutic skills at the end of the clerkship.

5-Oxoproline as a cause of high anion gap metabolic acidosis: an uncommon cause with common risk factors

High anion gap metabolic acidosis might be caused by 5-oxoproline (pyroglutamic acid). As it is very easy to treat, it might be worth drawing attention to this uncommon and probably often overlooked diagnosis. We present three cases of high anion gap metabolic acidosis due to 5-oxoproline seen within a period of six months.

[TNF-blocking drugs and infection; recommendations for daily practice]

Anti-tumour necrosis factor (TNF) therapy is associated with an increased risk of infection. There are sparse data and no evidence-based guidelines on how to deal with this problem in daily practice. However, recommendations can be made based on theoretical considerations and by extrapolating from recommendations for other types ofimmunodeficiency. Before starting anti-TNF therapy, screening for tuberculosis and other possible infections is indicated. During therapy, alertness is required to the increased risk of infection, infections with a more serious clinical course or unusual manifestations and opportunistic infections. Flu vaccination during anti-TNF therapy is indicated. Travel vaccinations with live microbial inocula should not be given.

The role of procalcitonin in a decision tree for prediction of bloodstream infection in febrile patients

Bloodstream infection (BSI) in febrile patients is associated with high mortality. Clinical and laboratory variables, such as procalcitonin (PCT), may predict BSI and help decision-making concerning empirical treatment. This study compared two models for prediction of BSI, and evaluated the role of PCT vs. clinical variables, collected daily in 300 consecutive febrile inpatients, for 48 h after onset of fever. Multiple logistic regression (MLR) and classification and regression tree (CART) models were compared for discriminatory power and diagnostic performance. BSI was present in 17% of cases. MLR identified the presence of intravascular devices, nadir albumin and thrombocyte counts, and peak temperature, respiratory rate and leukocyte counts, but not PCT, as independent predictors of BSI. In contrast, a peak PCT level of >2.45 ng/mL was the principal discriminator in the decision tree based on CART. The latter was more accurate (94%) than the model based on MLR (72%; p <0.01). Hence, the presence of BSI in febrile patients is predicted more accurately and by different variables, e.g., PCT, in CART analysis, as compared with MLR models. This underlines the value of PCT plus CART analysis in the diagnosis of a febrile patient.

[Persistent fever in a patient with Salmonella typhimurium gonarthritis]

A 65-year-old patient with systemic lupus erythematodes (SLE) developed fever and gonarthritis whilst taking prednisone and hydrochloroquine. Salmonella typhimurium, sensitive to amoxicillin, was grown in cultures of synovial fluid, blood and urine. After high dosages of intravenous amoxicillin, blood cultures and knee punctate became negative, but fever seemingly without a clinical focus persisted. By means of a fluoro-18-deoxyglucose positron emission tomography (FDG-PET) scan, an abscess was located in the left upper leg and successfully treated. In patients with impaired cell-mediated immunity, an extra-intestinal manifestation of Salmonella should be taken into consideration particularly if there appears to be no clinical focus. This may be detected by FDG-PET.

[Two HIV-positive men with anorectal lymphogranuloma venereum and hepatitis C: emerging sexually transmitted diseases]

Two men, aged 41 and 28 years, both known to be HIV-positive, contracted multiple sexually-transmitted diseases (STDs) through unprotected anal sexual contact. These included lymphogranuloma venereum (LGV) proctitis and hepatitis C. Recently in The Netherlands and Belgium there has been an outbreak of LGV proctitis in HIV-positive men who have sex with men, caused by Chlamydia trachomatis serovar L2, an STD which up to now has been rare in Europe. Due to information about the epidemic received a few days previously, the LGV proctitis in the second patient could be diagnosed and treated rapidly. The incidence of STDs in men having sex with men is increasing, also in HIV-positive men. STDs with ulcerative lesions, such as LGV, facilitate transmission of other pathogenic micro-organisms, including HIV. This, in combination with high-risk sexual behaviour such as unprotected anal sexual intercourse, will increase the chance of blood-blood contact and hence the chance of contracting multiple STDs concurrently. Hepatitis C is not normally considered as an STD, but ulcerative lesions in one of the partners combined with high-risk sexual behaviour enables the hepatitis C virus to be sexually transmitted.

[Stomach ache and fever after consumption of watercress in Turkey: fascioliasis]

A 52-year-old woman presented several months after returning from a visit to Turkey with stomach-ache and fever. Laboratory results showed leucocytosis with marked eosinophilia. Furthermore, serum liver enzyme activities were slightly elevated. A CT scan of the abdomen showed several spots which, on a later scan, had migrated. Serologic tests confirmed the clinical diagnosis of fascioliasis. The patient was successfully treated with triclabendazole. Infection presumably occurred after eating watercress which the patient had bought on a market in Turkey.

The effect of grapefruit juice on the time-dependent decline of artemether plasma levels in healthy subjects

BACKGROUND

Artemether is a new and effective treatment for malaria, although relapse is a problem in monotherapy. These relapses could be related to a time-dependent decline in artemether plasma levels described in multiple-dose studies and probably caused by autoinduction. The aim of this study was to evaluate the effect of grapefruit juice on the decreasing bioavailability over time of artemether.

METHODS

In a randomized, two-phase crossover study, eight healthy male subjects took 100 mg oral artemether with 350 mL water or with 350 mL double-strength fresh frozen grapefruit juice once daily for 5 days. On day 1 and day 5, 17 blood samples were collected over a period of 8 hours.

RESULTS

The mean peak artemether plasma concentration (Cmax) and the mean area under the concentration-time curve (AUC) after the last dose at day 5 were about one third compared with day 1, without a change in the elimination half-life after intake with water (P = .006 for Cmax; P = .005 for AUC) and with grapefruit juice (P < .001 for Cmax and AUC). Grapefruit juice increased Cmax (P = .021) and AUC (P < .001) twofold on day 1 (P = .021) and day 5 (P = .05 for Cmax; P = .004 for AUC). Dihydroartemisinin, the active metabolite, showed a twofold increase in Cmax (P = .006) and AUC (P = .001) with grapefruit juice, without time-dependent changes of pharmacokinetic parameters.

CONCLUSIONS

Grapefruit juice significantly increased the oral bioavailability of artemether but did not prevent the time-dependent reduction in bioavailability. It suggests that CYP3A4 in the gut wall is one of the metabolizing enzymes of artemether but seems to not be involved in the autoinduction process.

The development of an immunoassay for the detection of artemisinin compounds in urine

We have produced monoclonal antibodies against artelinic acid and investigated the reactivity with artemisinin drugs and metabolites. Antibody F170-10 is fairly specific for artelinic acid but does bind artemisinin and artemether (3-5% cross-reactivity). Dihydroartemisinin, artesunate, and metabolites of artemisinin showed less reactivity. With this antibody, an inhibition ELISA has been set up to detect artemisinin compounds in urine. In healthy subjects who received a single oral dose of artemisinin, artemether, artesunate or dihydroartemisinin, ELISA reactivity in urine was found. This reactivity in urine paralleled the plasma concentrations of artemether and dihydroartemisinin. The results show that this immunoassay for artelinic acid can be used to detect artemisinin compounds in urine for about 8 hr after intake. With a more sensitive test, this simple method as a urine dipstick may be become useful for drug use and compliance studies in malaria-endemic areas where the artemisinin derivatives are increasingly used.

Multiple dose pharmacokinetics of artemether in Chinese patients with uncomplicated falciparum malaria

Multiple dose pharmacokinetics of artemether and dihydroartemisinin were investigated in chinese patients treated for malaria. They received over 2 days either 4 x 80 mg artemether orally (n = 48) or 4 x 80-480 mg co-artemether (n = 40), a combination of artemether and lumefantrine (benflumetol). Lag time = 0.48 h (mean), Cmax after first dose = 157 ng/ml, t(max) = 1.73 h and elimination half-life = 1.16 h. The lag and absorption times were 0.5 h longer for co-artemether compared with artemether. Dihydroartemisinin paralleled artemether pharmacokinetics. Artemether Cmax after the last dose was one-third of the Cmax after the first dose while, inversely, dihydroartemisinin Cmax increased over time. We suggest that auto-induction of gut mucosa enzymes and/or liver enzymes causes a time-dependent increase in first-pass metabolisation of artemether.

Grapefruit juice increases the bioavailability of artemether

OBJECTIVE

To evaluate the effect of grapefruit juice on the pharmacokinetics of artemether in plasma and saliva after a single oral dose and to detect concentration-dependent electrocardiographic changes (bradycardia and QTc prolongation).

METHODS

Six healthy male subjects were given a standard breakfast followed by two tablets of 50-mg artemether administered with water; 1 week later, the tablets were administered with 350 ml double-strength fresh frozen grapefruit juice. For 8 h, 17 blood- and saliva samples were collected, and 17 electrocardiograms were recorded. Drug and metabolite concentrations were measured by means of high-performance liquid chromatography with electrochemical detection. The pharmacokinetic parameters were determined using a one-compartment model.

RESULTS

Grapefruit juice significantly (P = 0.001) increased the mean peak concentration (Cmax) of artemether more then twofold from 42 (SD 17) ng/ml to 107 (28) ng/ml. The time to reach Cmax (tmax) with grapefruit juice was 2.1 (0.6) h compared with 3.6 (17) h with water (P = 0.02). The area under the concentration time curve (AUC) almost doubled with grapefruit juice from 177 ng x h/ml to 336 ng x h/ml (P = 0.003). The elimination half-life remained unchanged (1.0 h vs 1.3 h). No major changes in the kinetics of the metabolite dihydroartemisinin were detected. Low artemether levels and zero dihydroartemisinin levels were found in saliva. No influences of artemether were observed on 17 electrocardiograms during the 8 h after drug intake in particular there were no signs of bradycardia or QTc prolongation.

CONCLUSION

Grapefruit juice significantly increases the oral bioavailability of artemether without an effect on the elimination half-life. It suggests a role for intestinal CYP3A4 in the presystemic metabolism of artemether.

Artemisinin drugs in the treatment of malaria: from medicinal herb to registered medication

Registration in Europe of several artemisinin drugs for the treatment of malaria can soon be expected. Artemisinin is isolated from the herb Artemisia annua, in use in China more than 2000 years as a herbal tea against fever. Artemisinin drugs are being used extensively in South-East Asia and increasingly in Africa. Active derivatives have been synthesized - artemether, arteether and artesunate - which are used for oral, intramuscular, rectal and intravenous administration. The origin, mechanism of action, efficacy and safety in patients, the pharmacokinetics and the position of this group of compounds among existing antimalarials are discussed in this review.

The contribution of the enzymes CYP2D6 and CYP2C19 in the demethylation of artemether in healthy subjects

The contribution of the enzymes CYP2D6 and CYP2C19 to the metabolism of artemether was evaluated in a cross-over study in seven healthy adult Caucasian subjects. The pharmacokinetic properties of artemether and its active metabolite dihydroartemisinin were compared when given 100 mg artemether orally alone or in combination with either CYP2D6-inhibitor quinidine or CYP2C19-inhibitor omeprazole. Plasma concentrations of artemether and dihydroartemisinin were measured with reversed phase high performance liquid chromatography with electro-chemical detection (HPLC-ED). Artemether was rapidly absorbed with a mean tmax of 0.8 h (95% confidence interval, CI=0.5-1.1) reaching a mean Cmax of 29 ng/ml (14-45 ng/ml). The mean elimination half-life was 1.3 h (0.8-1.8 h). The pharmacokinetic parameters for dihydroartemisinin were not significantly different from those for artemether. Artemether combined with quinidine revealed no significant changes in the plasma concentrations of either artemether or dihydroartemisinin. No changes were seen in the combination with omeprazole as a CYP2C19 inhibitor. A second peak in the plasma concentration profile was observed 2-4 h after drug intake. This phenomenon was possibly related to variable gastric emptying. No major contribution of the enzymes CYP2D6 or CYP2C19 was found in artemether metabolism. No interethnic differences in artemether metabolism on the basis of a genetic polymorphism of these enzymes is to be expected.

Validation of an improved reversed-phase high-performance liquid chromatography assay with reductive electrochemical detection for the determination of artemisinin derivatives in man

For the determination of artemisinin (ART) and analogs, a reversed-phase high-performance liquid chromatography method using reductive electrochemical detection (ED) was set up with some important modifications as compared to previously published assays. A different technique of deoxygenating resulted in a factor 2-3 lower background current. A Spectroflow 400 liquid chromatograph in combination with a Triathlon autoinjector coupled to a Decade electrochemical detector was used. The detector was operated in the reductive mode as a closed system under chromatography grade helium to exclude any access of oxygen. The Decade has a glassy carbon electrode and a reference Ag/AgCl electrode. Infrequent electropolishing was required implicating a very stable system. By increasing acetonitril or lowering the pH of the mobile phase, the various derivatives could be determined in the same chromatogram. The assay was validated using artemether (ATM) and dihydroartemisinin (DHA) as test substances. In the concentration range seen in people after usual doses (5 to 220 ng/ml), the assay performs with adequate accuracy and precision. The interassay and intraassay precision are < 6% for ATM. For DHA, the interassay and intraassay precision are < 9%. The accuracy expressed as the deviation from the expected concentration varies from -1% to +4.5% for the intraassay ATM-determinations and from +1% to +6.3% for the interassay measurements. For DHA, the accuracy is somewhat less, varying from -0.3% to -9.5% for the intraassay measurements and -0.6% to +2.6% for the interassay measurements. The reproducibility of the assay, measured over a time period of 3 months, is good for ATM and DHA with an interassay precision of < 18% in 70 repetitive samples and an accuracy varying from -0.6% to +7.6%. In a cross-check with two other reference laboratories who used comparable methods of determination, a strong correlation (correlation coefficient > 0.98) was achieved. The method was applied in a study in which artemether was administered orally to healthy white subjects. We consider high-performance liquid chromatography with electrochemical detection an accurate and precise method for quantitative determination of artemisinin derivatives in pharmacokinetic studies.

Antibiotic-induced endotoxin release in patients with gram-negative urosepsis: a double-blind study comparing imipenem and ceftazidime

The clinical significance of differences between antibiotics in endotoxin-liberating potential is unknown. Thirty patients with gram-negative urosepsis were randomized between imipenem and ceftazidime, which have, respectively, a low and a high endotoxin-liberating potential in vitro. In patients treated with ceftazidime, a slower defervescence was noticed. After 4 h of treatment, the blood endotoxin level decreased in all 3 endotoxemic patients receiving imipenem, whereas it increased in 2 of the 4 endotoxemic patients receiving ceftazidime, and in ceftazidime-treated patients, the endotoxin level in urine decreased less than in imipenem-treated subjects. Serum and urine cytokine levels increased 10%-40% after 4 h of ceftazidime treatment compared with no increase in the imipenem-treated patients (P > .05). Endotoxin release during antibiotic killing in vitro, assessed for all microorganisms, was 10-fold higher with ceftazidime (P < .001). These results indicate that differences between antibiotics in endotoxin release may affect the inflammatory response during treatment.

Acute chest syndrome in adult Afro-Caribbean patients with sickle cell disease. Analysis of 81 episodes among 53 patients

BACKGROUND

To evaluate the frequency, presentation, and course of the acute chest syndrome (ACS) in adult Afro-Caribbean patients with sickle cell disease (SCD).

PATIENTS AND METHODS

Retrospective cohort study during a 12-year period in patients with SCD at least 14 years of age, discharged with a diagnosis of ACS from the only hospital on the Caribbean island of Curaçao, where 109 patients with SCD (62 HbSS, 47 HbSC) were observed.

RESULTS

Eighty-one episodes of ACS occurred (57 in 34 patients with HbSS and 24 in 19 patients with HbSC). The risk (odds ratio, 1.80; P = .13) and incidence (7.6 vs 4.2 per 100 patient-years; P > .2) of ACS did not differ between patients with HbSS and HbSC, but recurrent ACS affected patients with HbSS more (odds ratio, 2.96; P = .09). Abnormal chest sounds (mainly bilateral crepitations) were found in 91% of cases at diagnosis, but 48% had normal chest roentgenograms at that time and had delayed development (5.4 +/- 3.4 days) of radiologic abnormalities. Patients with HbSS and HbSC had similar clinical presentations. Mortality (6%) and hospital stay (20 days) were not influenced by the use of transfusions or anticoagulation. All five nonsurviving female patients with HbSS had had more previous admissions for SCD and ACS.

CONCLUSIONS

Acute chest syndrome occurs in 42% of adult Afro-Caribbean patients with SCD; patients with HbSS are more prone to recurrences. Delayed development of radiologic infiltrates is common. Interventions apart from supportive care do not influence the course of ACS. Fatal ACS occurs in patients with a more severe form of SCD.

[Malignant neuroleptic syndrome: complete anticoagulant treatment or not?]

A case is reported, in which fatal pulmonary embolism complicated the course of a neuroleptic malignant syndrome (NMS). This syndrome includes several risk factors for the development of venous thromboembolism, such as: protracted immobility; severe rigidity causing a slowing of blood flow through the deep venous system; hypovolaemia with increased blood viscosity and activation of coagulation by rhabdomyolysis. An analysis of 115 case reports in the literature on NMS showed that 3 out of 13 patients with fatal NMS (23%) died of pulmonary embolism. The reviewed case, the literature findings and the risk factors mentioned cause us to believe that complete anticoagulant therapy may have a place in the therapeutic approach to patients with NMS.