Use of mefloquine in children - a review of dosage, pharmacokinetics and tolerability data

Antimalarial artesunate-mefloquine versus praziquantel in African children with schistosomiasis: an open-label, randomized controlled trial

Schistosomiasis treatment entirely relies on a single drug, praziquantel, prompting research into alternative therapeutics. Here we evaluated the efficacy and safety of the antimalarial combination artesunate-mefloquine for the treatment of schistosomiasis in a proof-of-concept, pragmatic, open-label, randomized controlled trial in primary schools of six villages endemic for schistosomiasis in northern Senegal. Children (6-14 years) were eligible if Schistosoma eggs were detected by microscopy in urine and/or stool. In total, 726 children were randomized 1:1 to praziquantel (standard care: 40 mg kg-1 single dose; n = 364) or to artesunate-mefloquine (antimalarial dosage: artesunate 4 mg kg-1 and mefloquine 8 mg kg-1 daily for three consecutive days; n = 362). Eight children not meeting the inclusion criteria were excluded from efficacy analysis. Median age of the remaining 718 participants was 9 years; 399 (55.6%) were male, and 319 (44.4%) female; 99.3% were infected with Schistosoma haematobium and 15.2% with S. mansoni. Primary outcomes were cure rate, assessed by microscopy, and frequency of drug-related adverse effects of artesunate-mefloquine versus praziquantel at 4 weeks after treatment. Cure rate was 59.6% (208/349) in the artesunate-mefloquine arm versus 62.1% (211/340) in the praziquantel arm. The difference of -2.5% (95% confidence interval (CI) -9.8 to 4.8) met the predefined criteria of noninferiority (margin set at 10%). All drug-related adverse events were mild or moderate, and reported in 28/361 children receiving artesunate-mefloquine (7.8%; 95% CI 5.4 to 11.0) versus 8/363 (2.2%; 95% CI 1.1 to 4.3) receiving praziquantel (P < 0.001). Artesunate-mefloquine at antimalarial dosage was moderately safe and noninferior to standard-care praziquantel for the treatment of schistosomiasis, predominantly due to S. haematobium. Multicentric trials in different populations and epidemiological settings are needed to confirm these findings. ClinicalTrials.gov identifier: NCT03893097 .

Rapid Study on Mefloquine Hydrochloride Complexation with Hydroxypropyl-β-Cyclodextrin and Randomly Methylated β-Cyclodextrin: Phase Diagrams, Nuclear Magnetic Resonance Analysis, and Stability Assessment

This study investigates the complexation of mefloquine hydrochloride by cyclodextrins to improve its solubility in order to design an oral solution. This approach may enhance the effectiveness of mefloquine, a drug which can be used for malaria prophylaxis and treatment in children. Mefloquine hydrochloride's solubility was assessed in different buffer solutions, and its quantification was achieved through high-performance liquid chromatography. The complexation efficiency with cyclodextrins was evaluated, and nuclear magnetic resonance (NMR) methods were employed to determine the interactions between mefloquine and cyclodextrins. Mefloquine's solubility increased when combined with hydroxypropyl-β-cyclodextrin (HP-β-CD) and randomly methylated β-cyclodextrin (RAMEB), with RAMEB being more effective. The drug's solubility varied across different pH buffers, being higher in acidic buffers. Interestingly, mefloquine's solubility decreased with a citrate buffer, possibly due to precipitation. The NMR studies highlighted non-covalent interactions between RAMEB, HP-β-CD, and mefloquine, explaining the solubilizing effect via complexation phenomena. Furthermore, the NMR experiments indicated the complexation of mefloquine by all the studied cyclodextrins, forming diastereoisomeric complexes. Cyclodextrin complexation improved mefloquine's solubility, potentially impacting its bioavailability.

Antimalarial treatment in infants

INTRODUCTION

Malaria in infants is common in high-transmission settings, especially in infants >6 months. Infants undergo physiological changes impacting pharmacokinetics and pharmacodynamics of anti-malarial drugs and, consequently, the safety and efficacy of malaria treatment. Yet, treatment guidelines and evidence on pharmacological interventions for malaria often fail to address this vulnerable age-group. This review aims to summarise the available data on anti-malarial treatment in infants.

AREAS COVERED

The standard recommended treatments for severe and uncomplicated malaria are generally safe and effective in infants. However, infants have an increased risk of drug-related vomiting and have distinct pharmacokinetic parameters of antimalarials compared with older patients. These include larger volumes of distribution, higher clearance rates and immature enzyme systems. Consequently, infants with malaria may be at increased risk of treatment failure and drug toxicity.

EXPERT OPINION

Knowledge expansion to optimize treatment can be achieved by including more infants in antimalarial drug trials and by reporting separately on treatment outcomes in infants. Additional evidence on the efficacy, safety, tolerability, acceptability and effectiveness of ACTs in infants is needed, as well as population pharmacokinetics studies on antimalarials in the infant population.

Development of Resistance Against Mefloquine Prophylaxis in Peace-Keeping Forces in the Central African Republic

Objective

To record the frequency of malaria-like symptoms in patients who have been given mefloquine as chemoprophylaxis and to determine the effectiveness of antimalarials against these symptoms.

Methodology

It was an observational study that took place at a United Nations Level 1 hospital, Kaga-Bandoro, Central African Republic. The total duration of the study was three months.

Patients presenting to the clinic with multiple symptoms despite chemoprophylaxis with mefloquine were assessed through a physical examination and screening test for malaria. Malaria treatment with a six-dose regimen of artemether (20 mg), along with lumefantrine (120 mg) two tablets BD for three days, was given after informed consent to those patients and post-treatment symptoms were observed and recorded.

Results

Out of 61 patients, 93% of them presented with body aches, 92% with headache, 52% with shivering, 44% with vertigo, 38% with fever, sweating, and nausea/vomiting, 18% with diarrhea, and 10% with pain in the abdomen.

Conclusion

It had been seen that patients presented with symptoms despite standard mefloquine prophylactic therapy, which were resolved with other antimalarial drugs. The presentation of the symptoms was also not classical.

Development and Characterization of the Solvent-Assisted Active Loading Technology (SALT) for Liposomal Loading of Poorly Water-Soluble Compounds

A large proportion of pharmaceutical compounds exhibit poor water solubility, impacting their delivery. These compounds can be passively encapsulated in the lipid bilayer of liposomes to improve their water solubility, but the loading capacity and stability are poor, leading to burst drug leakage. The solvent-assisted active loading technology (SALT) was developed to promote active loading of poorly soluble drugs in the liposomal core to improve the encapsulation efficiency and formulation stability. By adding a small volume (~5 vol%) of a water miscible solvent to the liposomal loading mixture, we achieved complete, rapid loading of a range of poorly soluble compounds and attained a high drug-to-lipid ratio with stable drug retention. This led to improvements in the circulation half-life, tolerability, and efficacy profiles. In this mini-review, we summarize our results from three studies demonstrating that SALT is a robust and versatile platform to improve active loading of poorly water-soluble compounds. We have validated SALT as a tool for improving drug solubility, liposomal loading efficiency and retention, stability, palatability, and pharmacokinetics (PK), while retaining the ability of the compounds to exert pharmacological effects.

Population Pharmacokinetics of Mefloquine Intermittent Preventive Treatment for Malaria in Pregnancy in Gabon

Mefloquine was evaluated as an alternative for intermittent preventive treatment of malaria in pregnancy (IPTp) due to increasing resistance against the first-line drug sulfadoxine-pyrimethamine (SP). This study determined the pharmacokinetic characteristics of the mefloquine stereoisomers and the metabolite carboxymefloquine (CMQ) when given as IPTp in pregnant women. Also, the relationship between plasma concentrations of the three analytes and cord samples was evaluated, and potential covariates influencing the pharmacokinetic properties were assessed. A population pharmacokinetic analysis was performed with 264 pregnant women from a randomized controlled trial evaluating a single and a split-dose regimen of two 15-mg/kg mefloquine doses at least 1 month apart versus SP-IPTp. Both enantiomers of mefloquine and its carboxy-metabolite (CMQ), measured in plasma and cord samples, were applied for pharmacokinetic modelling using NONMEM 7.3. Both enantiomers and CMQ were described simultaneously by two-compartment models. In the split-dose group, mefloquine bioavailability was significantly increased by 5%. CMQ induced its own metabolism significantly. Maternal and cord blood concentrations were significantly correlated (r ² = 0.84) at delivery. With the dosing regimens investigated, prophylactic levels are not constantly achieved. A modeling tool for simulation of the pharmacokinetics of alternative mefloquine regimens is presented. This first pharmacokinetic characterization of mefloquine IPTp indicates adequate exposure in both mefloquine regimens; however, concentrations at delivery were below previously suggested threshold levels. Our model can serve as a valuable tool for researchers and clinicians to develop and optimize alternative dosing regimens for IPTp in pregnant women.

Development of a physiologically based pharmacokinetic model for mefloquine and its application alongside a clinical effectiveness model to select an optimal dose for prevention of malaria in young Caucasian children

AIMS

To predict the optimal chemoprophylactic dose of mefloquine in infants of 5-10 kg using physiologically based pharmacokinetic (PBPK) and clinical effectiveness models.

METHODS

The PBPK model was developed in Simcyp version 14.1 and verified against clinical pharmacokinetic data in adults; the final model, accounting for developmental physiology and enzyme ontogeny was then applied in the paediatric population. The clinical effectiveness model utilized real-world chemoprophylaxis data with stratification of output by age and including infant data from the UK population.

RESULTS

PBPK simulations in infant populations depend on the assumed fraction of mefloquine metabolized by CYP3A4 (0.47, 0.95) and on the associated CYP3A4 ontogeny (Salem, Upreti). However, all scenarios suggest that a dose of 62.5 mg weekly achieves or exceeds the exposure in adults following a 250 mg weekly dose and results in a minimum plasma concentration of 620 ng ml^-1 , which is considered necessary to achieve 95% prophylactic efficacy. The clinical effectiveness model predicts a 96% protective efficacy from mefloquine chemoprophylaxis at 62.5 mg weekly.

CONCLUSIONS

The PBPK and clinical effectiveness models are mutually supportive and suggest a prophylactic dose of 62.5 mg weekly in the Caucasian 5-10 kg infant population travelling to endemic countries. This dual approach offers a novel route to dose selection in a vulnerable population, where clinical trials would be difficult to conduct.

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

INTRODUCTION

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

Pannexin-1 channel dysfunction in the medial prefrontal cortex mediates depressive-like behaviors induced by chronic social defeat stress and administration of mefloquine in mice

Mefloquine (MFQ) is widely used for the treatment of malaria clinically. Apart from antimalarial effect, psychiatric side effects such as depression and anxiety of MFQ have been reported. Interestingly, MFQ is also known as a broad-spectrum pannexin-1 (Panx1) inhibitor. Panx1 is a new gap junction channel in the brain which mediates efflux of adenosine triphosphate (ATP). Although exogenous ATP has been known to produce a potential antidepressant-like effect, little is known about the role of Panx1 in pathophysiology of depression, especially the depression induced by administration of MFQ. Here, we used the chronic social defeat stress (CSDS) model and found a decrease in the expression and function of Panx1 in the medial prefrontal cortex (mPFC) of susceptible mice. Furthermore, pharmacological blockade of Panx1 in the mPFC with carbenoxolone (CBX) (100 mM) or ¹⁰Panx (100 μM) was sufficient to induce depressive-like behaviors and increase vulnerability to stress in mice, which were prevented by preconditioning with ATP (25 μM). Finally, systemic and intral-mPFC injection of MFQ both inhibited the activity of Panx1 and induced depressive-like and anxiety behaviors in mice with sub-threshold social defeat stress. Indeed, the behavioral abnormalities induced by MFQ were prevented by preconditioning with ATP in the mPFC. In conclusion, our study demonstrates a role of the Panx1 channel in chronic stress and MFQ-induced depressive-like and anxiety behaviors, which may provide a novel molecular mechanism for psychiatric side effects of MFQ.

Mefloquine in the nucleus accumbens promotes social avoidance and anxiety-like behavior in mice

Mefloquine continues to be a key drug used for malaria chemoprophylaxis and treatment, despite reports of adverse events like depression and anxiety. It is unknown how mefloquine acts within the central nervous system to cause depression and anxiety or why some individuals are more vulnerable. We show that intraperitoneal injection of mefloquine in mice, when coupled to subthreshold social defeat stress, is sufficient to produce depression-like social avoidance behavior. Direct infusion of mefloquine into the nucleus accumbens (NAc), a key brain reward region, increased stress-induced social avoidance and anxiety behavior. In contrast, infusion into the ventral hippocampus had no effect. Whole cell recordings from NAc medium spiny neurons indicated that mefloquine application increases the frequency of spontaneous excitatory postsynaptic currents, a synaptic adaptation that we have previously shown to be associated with increased susceptibility to social defeat stress. Together, these data demonstrate a role for the NAc in mefloquine-induced depression and anxiety-like behaviors.

The elderly, the young and the pregnant traveler -- A retrospective data analysis from a large Swiss Travel Center with a special focus on malaria prophylaxis and yellow fever vaccination

BACKGROUND

Vulnerable individuals such as elderly, children/adolescents and pregnant/breastfeeding women increasingly travel overseas. We describe the travel and vaccination patterns of these groups at the largest Travel Clinic in Switzerland especially focusing on travel to yellow fever and malaria-endemic countries, and yellow fever vaccination (YFV) and malaria medications.

METHOD

An analysis of pre-travel visits between 2010 and 2012 at the Travel Clinic of the University of Zurich, was performed assessing differences between the elderly, young and middle-aged travelers as well as between pregnant/breastfeeding and other female travelers.

RESULTS

Overall, the vulnerable groups did not differ from other travelers regarding their travel patterns. YFV was the most often administered vaccine to elderly travelers; half of them received it for the first time. More than 30% of children/adolescents received YFV, but no child below six months was vaccinated. 80% of young travelers and a similar percentage of pregnant women went to malaria-endemic regions. Twenty-five pregnant/breastfeeding women traveled to YF endemic areas.

CONCLUSIONS

Travel patterns of vulnerable travelers are comparable to those of other travelers. In view of the limited data on malaria medications and precautions against YFV during pregnancy and at the extreme ages of life, giving travel advice to these groups is challenging.

Knowledge, attitudes, and practices concerning malaria in pregnancy: results from a qualitative study in Madang, Papua New Guinea

Background

Malaria is the leading cause of illness and death in Papua New Guinea (PNG). Infection during pregnancy with falciparum or vivax malaria, as occurs in PNG, has health implications for mother and child, causing complications such as maternal anemia, low birth weight and miscarriage. This article explores knowledge, attitudes and practices concerning malaria during pregnancy and it’s prevention in Madang, PNG, a high prevalence area.

Methods

As part of a qualitative study in Madang, exploring MiP, participatory techniques (free-listing and sorting) were conducted along with focus group discussions, in-depth interviews (with pregnant women, health staff and other community members) and observations in the local community and health facilities.

Results

The main themes explored were attitudes towards and knowledge of MiP, its risks, and prevention. Although there was a general awareness of the term “malaria”, it was often conflated with general sickness or with pregnancy-related symptoms. Moreover, many preventive methods for MiP were related to practices of general healthy living. Indeed, varied messages from health staff about the risks of MiP were observed. In addition to ideas about the seriousness and risk of MiP, other factors influenced the uptake of interventions: availability and perceived comfort of sleeping under insecticide-treated mosquito nets were important determinants of usage, and women’s heavy workload influenced Chloroquine adherence.

Conclusion

The non-specific symptoms of MiP and its resultant conflation with symptoms of pregnancy that are perceived as normal have implications for MiP prevention and control. However, in Madang, PNG, this was compounded by the inadequacy of health staff’s message about MiP.

A Randomized Trial to Compare the Safety, Tolerability, and Effectiveness of 3 Antimalarial Regimens for the Prevention of Malaria in Nigerian Patients With Sickle Cell Disease

BACKGROUND

Malaria prophylaxis is recommended for persons with sickle cell disease (SCD), but the value of this has been questioned. The aim of this study was to find out whether intermittent preventive treatment (IPT) with a fixed-dose combination of mefloquine-artesunate (MQAS) or sulfadoxine-pyrimethamine plus amodiaquine (SPAQ) was more effective than daily proguanil for malaria prevention in subjects with SCD.

METHODS

Patients with SCD were randomized to receive daily treatment with proguanil or IPT with either MQAS or SPAQ once every 2 months at routine clinic visits. Patients were followed up for 14 months.

FINDINGS

A total of 270 patients with SCD were studied, with 90 in each group. Adherence to the IPT regimens was excellent, but 57% of patients took <75% of their daily doses of proguanil. IPT was well tolerated; the most common side effects were vomiting and abdominal pain. Protective efficacy against malaria, compared with daily proguanil, was 61% (95% confidence interval, 3%-84%) for MQAS and 36% (40%-70%) for SPAQ. There were fewer outpatient illness episodes in children who received IPT than those who received proguanil.

CONCLUSIONS

IPT with MQAS administered to patients with SCD during routine clinic visits was well tolerated and more effective in preventing malaria than daily prophylaxis with proguanil.

CLINICAL TRIALS REGISTRATION

NCT01319448 and ISRCTN46158146.

Mefloquine and psychotomimetics share neurotransmitter receptor and transporter interactions in vitro

RATIONALE

Mefloquine is used for the prevention and treatment of chloroquine-resistant malaria, but its use is associated with nightmares, hallucinations, and exacerbation of symptoms of post-traumatic stress disorder. We hypothesized that potential mechanisms of action for the adverse psychotropic effects of mefloquine resemble those of other known psychotomimetics.

OBJECTIVES

Using in vitro radioligand binding and functional assays, we examined the interaction of (+)- and (-)-mefloquine enantiomers, the non-psychotomimetic anti-malarial agent, chloroquine, and several hallucinogens and psychostimulants with recombinant human neurotransmitter receptors and transporters.

RESULTS

Hallucinogens and mefloquine bound stereoselectively and with relatively high affinity (K i = 0.71-341 nM) to serotonin (5-HT) 2A but not 5-HT1A or 5-HT2C receptors. Mefloquine but not chloroquine was a partial 5-HT2A agonist and a full 5-HT2C agonist, stimulating inositol phosphate accumulation, with similar potency and efficacy as the hallucinogen dimethyltryptamine (DMT). 5-HT receptor antagonists blocked mefloquine's effects. Mefloquine had low or no affinity for dopamine D1, D2, D3, and D4.4 receptors, or dopamine and norepinephrine transporters. However, mefloquine was a very low potency antagonist at the D3 receptor and mefloquine but not chloroquine or hallucinogens blocked [(3)H]5-HT uptake by the 5-HT transporter.

CONCLUSIONS

Mefloquine, but not chloroquine, shares an in vitro receptor interaction profile with some hallucinogens and this neurochemistry may be relevant to the adverse neuropsychiatric effects associated with mefloquine use by a small percentage of patients. Additionally, evaluating interactions with this panel of receptors and transporters may be useful for characterizing effects of other psychotropic drugs and for avoiding psychotomimetic effects for new pharmacotherapies, including antimalarial quinolines.

Paediatric travel medicine: vaccines and medications

The paediatric aspects of travel medicine can be complex, and individual advice is often required. Nonetheless, children are much more likely to acquire common infections than exotic tropical diseases whilst travelling. Important exceptions are malaria and tuberculosis, which are more frequent and severe in children. Overall, travellers' diarrhoea is the most common illness affecting travellers. This review discusses vaccines and medications that may be indicated for children who are travelling overseas. It focuses on immunizations that are given as part of the routine schedule, as well as those that are more specific to travel. Malaria and travellers' diarrhoea are also discussed.

Epilepsy triggered by mefloquine in an adult traveler to Uganda

We report a case of a traveler who visited Uganda for 8 d, and took mefloquine one tablet/week for malaria prophylaxis. After the second dose, he suffered from two episodes of loss of consciousness with seizures, therefore mefloquine was discontinued. During the flight back after full recovery, seizures reoccurred while he was on board, he was disembarked in Addis Ababa and then transferred to Nairobi. After repatriation to Italy, he experienced four other similar episodes. The patient was still on full dose anticonvulsant therapy one year and a half after, as any attempt at reduced dose was unsuccessful. Currently, three agents (mefloquine, atovaquone/proguanil, and doxycycline) are recommended for malaria chemoprophylaxis, with similar efficacy but different adverse event profiles, regimens, and prices. Considering that mefloquine is associated with a higher risk of neurologic and psychiatric adverse events than the alternative regimens, we suggest considering mefloquine as a second line choice after atovaquone/proguanil and doxycycline for short-term travelers.

Failure of malaria chemoprophylaxis with mefloquine in an oversize traveller to Mozambique

A case of failure of mefloquine prophylaxis in an oversize traveller, who correctly took the drug. This case seems to be attributed to mefloquine resistance, however it is suggested that mefloquine dosage should be modulated by body weight, as is already indicated by some authorities.

Pre-Travel Health Preparation of Pediatric International Travelers: Analysis From the Global TravEpiNet Consortium

BACKGROUND

Children frequently travel internationally. Health-related data on such children are limited. We sought to investigate the demographics, health characteristics, and preventive interventions of outbound US international pediatric travelers.

METHODS

We analyzed data from 32 099 travelers presenting for pre-travel healthcare at the Global TravEpiNet (GTEN), a national consortium of 19 travel clinics, from January 1, 2009 to June 6, 2012.

RESULTS

A total of 3332 (10%) of all GTEN travelers were children (<18 years of age). These children traveled mostly for leisure (36%) or to visit friends or relatives (VFR) (36%). Most popular destination regions were Africa (41%), Southeast Asia (16%), Central America (16%), and the Caribbean (16%). Compared with children traveling for leisure, VFR children were more likely to present <14 days before departure for pre-travel consultation (44% vs 28%), intended to travel for 28 days or longer (70% vs 22%), and to travel to Africa (62% vs 32%). Nearly half of the pediatric travelers (46%) received at least 1 routine vaccine, and most (83%) received at least 1 travel-related vaccine. Parents or guardians of one third of the children (30%) refused at least 1 recommended travel-related vaccine. Most pediatric travelers visiting a malaria-endemic country (72%) received a prescription for malaria chemoprophylaxis.

CONCLUSIONS

Ten percent of travelers seeking pre-travel healthcare at GTEN sites are children. VFR-travel, pre-travel consultation close to time of departure, and refusal of recommended vaccines may place children at risk for travel-associated illness. Strategies to engage pediatric travelers in timely, pre-travel care and improve acceptance of pre-travel healthcare interventions are needed.

Comparative safety of artemether-lumefantrine and other artemisinin-based combinations in children: a systematic review

Background

The purpose of the study was to compare the safety of artemether-lumefantrine (AL) with other artemisinin-based combinations in children.

Methods

A search of EMBASE (from 1974 to April 2013), MEDLINE (from 1946 to April 2013) and the Cochrane library of registered controlled trials for randomized controlled trials (RCTs) which compared AL with other artemisinin-based combinations was done. Only studies involving children ≤ 17 years old in which safety of AL was an outcome measure were included.

Results

Four thousand, seven hundred and twenty six adverse events (AEs) were recorded in 6,000 patients receiving AL. Common AEs (≥1/100 and <1/10) included: coryza, vomiting, anaemia, diarrhoea, vomiting and abdominal pain; while cough was the only very commonly reported AE (≥1/10). AL-treated children have a higher risk of body weakness (64.9%) than those on artesunate-mefloquine (58.2%) (p = 0.004, RR: 1.12 95% CI: 1.04-1.21). The risk of vomiting was significantly lower in patients on AL (8.8%) than artesunate-amodiaquine (10.6%) (p = 0.002, RR: 0.76, 95% CI: 0.63-0.90). Similarly, children on AL had a lower risk of vomiting (1.2%) than chlorproguanil-dapsone-artesunate (ACD) treated children (5.2%) (p = 0.002, RR: 0.63, 95% CI: 0.47-0.85). The risk of serious adverse events was significantly lower for AL (1.3%) than ACD (5.2%) (p = 0.002, RR: 0.45, 95% CI: 0.27-0.74).

Conclusion

Artemether-lumefantrine combination is as safe as ASAQ and DP for use in children. Common adverse events are cough and gastrointestinal symptoms. More studies comparing AL with artesunate-mefloquine and artesunate-azithromycin are needed to determine the comparative safety of these drugs.

Current challenges in travelers' malaria

Travel health providers are often confronted with complex scenarios when advising travelers on malaria prevention. Current challenges in prevention include malaria risk assessment, where a detailed itinerary and knowledge of malaria epidemiology are needed. Up-to-date information on the correct use, limitations, and drug interactions of current priority chemoprophylaxis agents (atovaquone/proguanil, mefloquine, doxycycline) is key. Another challenge is to identify and reach travelers who are most at risk of malaria, such as the traveler visiting friends and relatives. Posttravel, delays in presentation, diagnosis, and inappropriate treatment of malaria are key risk factors leading to death. Treatment of malaria is an emergency requiring expert in-patient management and referral to a center with adequate expertise. Artemisinin combination therapies are the drugs of choice for uncomplicated malaria. Complicated malaria is treated preferably with intravenous artesunate, and the supply and quality of this life-saving antimalarial in some settings can pose one of the most urgent challenges in travelers' malaria.

Efficacy and tolerability of a new formulation of artesunate-mefloquine for the treatment of uncomplicated malaria in adult in Senegal: open randomized trial

Background

Prompt treatment of malaria attacks with arteminisin-based combination therapy (ACT) is an essential tool for malaria control. A new co-blister tablet of artesunate-mefloquine (AM) with 25 mg/kg mefloquine has been developed for the management of uncomplicated malaria attacks. This non-inferiority randomized trial, was conducted to evaluate the efficacy and safety of the new formulation of AM in comparison to artemether-lumefantrine (AL) for the treatment of acute uncomplicated Plasmodium falciparum malaria in adults in Senegal.

Methods

The study was carried out from September to December 2010 in two health centres in Senegal. The study end points included (i) PCR corrected adequate clinical and parasitological response (ACPR) at day 28, (ii) ACPR at days 42 and 63, (iii) parasites and fever clearance time, (iv) incidence of adverse events and patients biological profile at day 7 using the WHO 2003 protocol for anti-malarial drug evaluation.

Results

Overall, 310 patients were randomized to receive either AM (n = 157) or AL (n = 153). PCR corrected ACPR at day 28 was at 95.5% in the AM arm while that in the AL arm was at 96.7% (p = 0.83). Therapeutic efficacy was at 98.5% in the AM arm versus 98.2% in the AL group at day 42 (p = 1). At day 63, ACPR in the AM and AL arms was at 98.2% and 97.7%, respectively (p = 0.32). The two treatments were well tolerated with similar biological profile at day 7. However, dizziness was more frequent in the AM arm.

Conclusion

Artesunate-mefloquine (25 mg/Kg mefloquine) is efficacious and well-tolerated for the treatment of uncomplicated P. falciparum malaria in adult patients.

Demographics, health and travel characteristics of international travellers at a pre-travel clinic in Marseille, France

With the aim to identify at-risk individuals among a cohort of international travellers, 3442 individuals who sought advice at Marseille travel health centre in 2009 were prospectively included. Demographics, travel characteristics, chronic medical conditions, vaccinations and antimalarial chemoprophylaxis were documented. Chronic medical conditions were reported by 11% of individuals, including hypertension (39%), asthma (20%), thyroid disease (15%) and depression (13%). 4% reported taking a daily medication, and psychotropic and cardiovascular medications were the most commonly used. Older travellers (≥60 years) accounted for 10% of the travellers and the prevalence of chronic medical conditions was 27% in this group. Individuals aged 15 years or less accounted for 13% of the travellers. Age, last minute travel (17%) and neurological and psychiatric diseases were the most frequent factors that influenced Yellow fever vaccination and malaria chemoprophylaxis, with more than one tenth of the travellers reporting at least one risk factor for which adjusted advice may be necessary. Migrants visiting their relatives in their origin country accounted for 14% of travellers and 73% of this group travelled with their family including young children. We demonstrate that a significant proportion of travellers are at-risk (43%) because of their travel conditions (VFR), their age, or their health status, and should be targeted for risk reduction strategies.

Therapeutic efficacy and safety of dihydroartemisinin-piperaquine versus artesunate-mefloquine in uncomplicated Plasmodium falciparum malaria in India

BACKGROUND

Resistance in Plasmodium falciparum to commonly used anti-malarial drugs, especially chloroquine, is being increasingly documented in India. By 2007, the first-line treatment for uncomplicated malaria has been revised to recommend artemisinin-based combination therapy (ACT) for all confirmed P. falciparum cases.

OBJECTIVE

The objective of this study was to compare the efficacy, safety and tolerability between dihydroartemisinin-piperaquine (DP) and artesunate plus mefloquine (A + M) drug combinations in the treatment of uncomplicated P. falciparum malaria in India.

METHODS

Between 2006 and 2007, 150 patients with acute uncomplicated P. falciparum malaria were enrolled, randomized to DP (101) or A + M (49) and followed up for 63 days as part of an open-label, non-inferiority, randomized, phase III multicenter trial in Asia.

RESULTS

The heterogeneity analysis showed no statistically significant difference between India and the other countries involved in the phase III study, for both the PCR-corrected and uncorrected cure rates. As shown at the whole study level, both forms of ACT were highly efficacious in India. In fact, in the per protocol population, the 63-day cure rates were 100% for A + M and 98.8% for DP. The DP combination exerted a significant post-treatment prophylactic effect, and compared with A + M a significant reduction in the incidence of new infections for DP was observed (respectively 17.1% versus 7.5% of patients experienced new infection within follow up). Parasite and fever clearance was rapid in both treatment arms (median time to parasite clearance of one day for both groups). Both DP and A + M were well tolerated, with the majority of adverse events of mild or moderate severity. The frequencies of individual adverse events were generally similar between treatments, although the incidence of post treatment adverse events was slightly higher in patients who received A + M with respect to those treated with DP.

CONCLUSION

DP is a new ACT displaying high efficacy and safety in the treatment of uncomplicated P. falciparum malaria and could potentially be considered for the first-line treatment of uncomplicated falciparum malaria in India.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN 81306618.