Division of Communicable Diseases, and Division of Biostatistics, Institute for Social and Preventive Medicine, University of Zurich, Division of Parasitic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, U.S. Army Research Institute of Environmental Medicine, Department of Behavioral Biology, Walter Reed Army Institute of Research, Rollins School of Public Health of Emory University, Department of Clinical Pharmacology, F. Hoffmann-La Roche Ltd., Zurich, Switzerland
Due to presumed adverse performance impact, a World Health Organization clause currently restricts the use of mefloquine malaria chemoprophylaxis in individuals requiring fine coordination and spatial discrimination. We conducted a double-blind, placebo-controlled, cross-over study to quantitatively assess the effects of mefloquine at steady state on performance in 23 trainee airline pilots. Flying performance was assessed using a flight simulator, psychomotor function was evaluated, sleep and wake cycles were monitored, and symptoms and moods were assessed using standardized questionnaires. A simplified postural sway meter recorded sway in three test positions. In the mefloquine loading dose phase, there was one withdrawal due to dizziness, diarrhea, and flu-like symptoms, and three volunteers reported nonserious, sleep-related adverse events. There was no significant difference in flying performance, psychomotor functions, or mean sway for any test position. Nonsignificant reductions in mean total nocturnal sleep (mefloquine = 450 min versus placebo = 484 min) and poorer sleep quality were detected in the mefloquine phases. The mood findings indicated a predominance of positive states, with vigor the predominant mood in all phases. No significant performance deficit was documented under laboratory conditions during use of mefloquine at steady state.