Mefloquine - Science
• Anti-malarial drugs and the prevention of malaria in the population of malaria endemic areas
Malar J. 2010 Dec 13;9 Suppl 3:S2.
Anti-malarial drugs can make a significant contribution to the control of malaria in endemic areas when used for prevention as well as for treatment. Chemoprophylaxis is effective in preventing deaths and morbidity from malaria, but it is difficult to sustain for prolonged periods, may interfere with the development of naturally acquired immunity and will facilitate the emergence and spread of drug resistant strains if applied to a whole community. However, chemoprophylaxis targeted to groups at high risk, such as pregnant women, or to periods of the year when the risk from malaria is greatest, can be an effective and cost effective malaria control tool and has fewer drawbacks. Intermittent preventive treatment, which involves administration of anti-malarials at fixed time points, usually when a subject is already in contact with the health services, for example attendance at an antenatal or vaccination clinic, is less demanding of resources than chemoprophylaxis and is now recommended for the prevention of malaria in pregnant women and infants resident in areas with medium or high levels of malaria transmission. Intermittent preventive treatment in older children, probably equivalent to targeted chemoprophylaxis, is also highly effective but requires the establishment of a specific delivery system. Recent studies have shown that community volunteers can effectively fill this role. Mass drug administration probably has little role to play in control of mortality and morbidity from malaria but may have an important role in the final stages of an elimination campaign.
• The position of mefloquine as a 21st century malaria chemoprophylaxis
Schlagenhauf P, Adamcova M, Regep L, Schaerer MT, Rhein HG.
Malar J. 2010 Dec 9;9:357.
BACKGROUND: Malaria chemoprophylaxis prevents the occurrence of the symptoms of malaria. Travellers to high-risk Plasmodium falciparum endemic areas need an effective chemoprophylaxis. METHODS: A literature search to update the status of mefloquine as a malaria chemoprophylaxis. RESULTS: Except for clearly defined regions with multi-drug resistance, mefloquine is effective against the blood stages of all human malaria species, including the recently recognized fifth species, Plasmodium knowlesi. New data were found in the literature on the tolerability of mefloquine and the use of this medication by groups at high risk of malaria. DISCUSSION: Use of mefloquine for pregnant women in the second and third trimester is sanctioned by the WHO and some authorities (CDC) allow the use of mefloquine even in the first trimester. Inadvertent pregnancy while using mefloquine is not considered grounds for pregnancy termination. Mefloquine chemoprophylaxis is allowed during breast-feeding. Studies show that mefloquine is a good option for other high-risk groups, such as long-term travellers, VFR travellers and families with small children. Despite a negative media perception, large pharmaco-epidemiological studies have shown that serious adverse events are rare. A recent US evaluation of serious events (hospitalization data) found no association between mefloquine prescriptions and serious adverse events across a wide range of outcomes including mental disorders and diseases of the nervous system. As part of an in-depth analysis of mefloquine tolerability, a potential trend for increased propensity for neuropsychiatric adverse events in women was identified in a number of published clinical studies. This trend is corroborated by several cohort studies that identified female sex and low body weight as risk factors. CONCLUSION: The choice of anti-malarial drug should be an evidence-based decision that considers the profile of the individual traveller and the risk of malaria. Mefloquine is an important, first-line anti-malarial drug but it is crucial for prescribers to screen medical histories and inform mefloquine users of potential adverse events. Careful prescribing and observance of contraindications are essential. For some indications, there is currently no replacement for mefloquine available or in the pipeline
• Malaria chemoprophylaxis: strategies for risk groups.
Schlagenhauf P, Petersen E.
Clin Microbiol Rev. 2008 Jul;21(3):466-72.
The risk of malaria for travelers varies from region to region and depends on the intensity of transmission, the duration of the stay in the area of endemicity, the style of travel, and the efficacy of preventive measures. The decision to recommend chemoprophylaxis to travelers to areas with a low risk of malarial infection is especially difficult because the risk of infection must be balanced with the risk of experiencing side effects. If the risk of side effects by far exceeds the risk of infection, the traveler needs information on measures against mosquito bites and advice on prompt diagnosis and self-treatment. The risk is difficult to quantify, and the absolute risk for travelers to most areas is not known, especially because the populations at risk are unknown. We propose here that the best approximation of the risk to the traveler to a specific area is to use the risk to the indigenous population as a guideline for the risk to the traveler, and we provide examples on how risk in the indigenous population can be used for the estimation of risk of malarial infection for travelers. Special groups are long-term visitors and residents, who often perceive risk differently, cease using chemoprophylaxis, and rely on self-diagnosis and treatment. For long-term visitors, the problem of fake drugs needs to be discussed. Strategies for chemoprophylaxis and self-treatment of pregnant women and small children are discussed. So far, malaria prophylaxis is recommended to prevent Plasmodium falciparum infections, and primaquine prophylaxis against persistent Plasmodium vivax and Plasmodium ovale infections in travelers is not recommended.
• Questionnaire-based analysis of mefloquine chemoprophylaxis for malaria in a Japanese population.
Matsumura T, Fujii T, Miura T, Koibuchi T, Endo T, Nakamura H, Odawara T, Iwamoto A, Nakamura T.
J Infect Chemother. 2005 Aug;11(4):196-8.
Although mefloquine is the only drug licensed for malaria chemoprophylaxis in Japan, there have been few reports describing the effects of and adverse events in the prophylactic usage of mefloquine in a Japanese population. We therefore performed a questionnaire-based study in 21 travelers who were prescribed mefloquine for malaria chemoprophylaxis between October 2001 and December 2003. The study revealed that only 8 out of 21 (38.1%) of the travelers could complete the prophylaxis schedules. Another 8 travelers (38.1%) with incomplete adherence stated that they did not take mefloquine because of either actually experienced or anticipated adverse events. Twelve of the 16 travelers (75.0%) who took mefloquine complained of at least one adverse event probably related to mefloquine. As an overall impression about mefloquine chemoprophylaxis, 14 of the 21 travelers stated that they would take mefloquine again for the next travel to malaria-endemic areas, although 5 of them were concerned about adverse events. These results suggest that, although mefloquine is an indispensable drug for malaria prevention, other effective and well-tolerated chemoprophylactic antimalarials should be available for Japanese travelers who do not tolerate mefloquine.