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Malaria: Effectiveness and side effects of mefloquine examined in reviews

Researchers from the Liverpool School of Tropical Medicine (LSTM) Cochrane Infectious Diseases Group published two systematic reviews this week about the safety of mefloquine (Lariam) for preventing malaria in travellers.

Malaria life cycle/CDC

“Mefloquine is at least as effective as other options” says Dr Tickell-Painter, the lead author on both papers, “but patients and policy-makers also need reliable information about common side-effects to make informed decisions’. Mefloquine has been linked with psychological side effects since its introduction in the 1980s, and the Cochrane review published on Monday now brings together over 50 randomized and non-randomized studies, enrolling over 1,000,000 people, and compares mefloquine with  alternatives in common use.

“There is no doubt that mefloquine does cause more sleeplessness, abnormal dreams, anxiety and depressed mood than the alternatives” says Dr Tickell-Painter, “but the review clarifies that these are symptoms reported by people taking mefloquine and not formal psychiatric diagnoses. Serious side effects with mefloquine seem to be rare, less than 1% of users, and increases in formal diagnoses of depression and psychosis have not been seen in people returning from travel in any of the large database studies.”

Mefloquine: Health Canada finds limited evidence supporting that long-lasting and permanent neurological and psychiatric adverse events

The researchers continued their investigation of the severity of these effects in their second paper published today in the journal Travel Medicine and Infectious Diseases. This paper used systematic methods to search for and appraise all case reports of deaths and attempted suicides associated with mefloquine. From 527 reports, the authors could only reliably attribute causality for one attempted suicide and a probable association for two deaths, which appeared to be atypical drug reactions. The authors considered all other reports of links unlikely or containing insufficient information to make a judgement.

“We hope that our review provides clarity in the debate about mefloquine” continued Dr Tickell-Painter, “and by providing more reliable estimates of the frequency and severity of common side effects, we can ensure proper informed discussions between doctors and patients about the relative merits of mefloquine, atovaquone-proguanil (Malarone), and doxycycline”

Tickell-Painter, Maya et al. Deaths and parasuicides associated with mefloquine chemoprophylaxis: A systematic review(link is external).   Travel Medicine and Infectious Disease 2017 in press

Tickell-Painter MMaayan NSaunders RPace CSinclair DMefloquine for preventing malaria during travel to endemic areas(link is external)Cochrane Database of Systematic Reviews 2017, Issue 10. Art. No.: CD006491. DOI:10.1002/14651858.CD006491.pub4.