Malaria – breakthrough in understanding the side effects of mefloquine

Two British scientists, Dr Ashley Croft and Dr Andrew Herxheimer, have published a paper which for the first time tries to explain the adverse effects of the controversial antimalaria drug, mefloquine (Lariam®).

Mefloquine, made by the Swiss drug company Hoffmann-La Roche, is used both to treat and prevent malaria. Since the 1980s doctors have used it to treat around 2 million people with malaria, and about 15 million travellers have used mefloquine as malaria prophylaxis.

Although many mefloquine users tolerate the drug well, in others it can cause a wide range of neuropsychiatric and other disturbing side effects, including hallucinations, nightmares, anxiety, tremor and psychosis. The first randomised controlled trial of mefloquine use in general travellers was published late last year in Clinical Infectious Diseases. One-third of the travellers using mefloquine reported neuropsychiatric adverse effects, and 6% of all mefloquine users reported at least one adverse event serious enough to require medical advice.