A comparative clinical trial of two different regimens of artemether plus mefloquine in multidrug resistant falciparum malaria.

Plasmodium falciparum in Thailand is highly resistant to available antimalarial drugs. Artemether, a derivative of artemisinin, is a promising compound currently used to cope with this situation but the course of treatment has to be at least 5 d. An effective short treatment course of this drug is possible when used in combination with mefloquine. We now report a trial of different regimens of the combination artemether/mefloquine. Fifty-seven male Thai patients, admitted to the Bangkok Hospital for Tropical Diseases, were allocated at random to receive oral artemether 300 mg as an initial dose, followed by either the standard dose of mefloquine (750 mg) at 24 h or a higher dose of mefloquine (750 mg at 24 h, then 500 mg at 30 h). Patients were followed up in hospital for 42 d. Two patients, both in the high dose mefloquine group, were excluded as they failed to attend for follow-up. All patients had a rapid initial response to treatment with median parasite clearance times of 37 and 40 h, median fever clearance times of 33.5 and 30.5 h, and cure rates of 75 and 96% (P = 0.0248), for the standard and high doses of mefloquine respectively. No serious adverse effect was found; mild and transient dizziness, nausea, vomiting and diarrhoea were noted in half of the patients in each group. The results suggest that a 30 h short course of artemether plus mefloquine at high dose should be used in areas with documented mefloquine resistance.