Aims: We performed a prospective cohort study to gain more insight into risk factors for neuropsychiatric effects of mefloquine among tourists travelling to tropical areas. Methods: We enrolled all patients who consulted the Travel Clinic of the Havenziekenhuis & Institute for Tropical Diseases Rotterdam for mefloquine prophylaxis during the period between 1 May 1999 and 7 March 2000. Each patient was followed from baseline (prior to starting mefloquine) up to 3 weeks after starting weekly intake of 250 mg mefloquine. We compared the intraindividual change in scores between baseline and follow-up visit on the Dutch shortened Profile of Mood States, and on the Continuous Performance Test (CPT) which measures sustained attention. Results: The final cohort consisted of 151 subjects with a mean age of 38 years. In this population, a significant impairment of mood state was observed in those with a body mass index (BMI) ≤20 kg m -2. Stratification for gender showed that the total mood disturbance in females in the lowest BMI category significantly increased by 8.42 points [95% confidence interval (CI) 3.33, 13.50], whereas BMI did not affect the risk in males. Stratification for history of use of mefloquine showed that the risks were highest in first-time users. Analyses of the CPT showed that reaction time in women with a BMI ≤20 kg m -2 increased significantly by 22.5 ms (95% CI 7.80, 37.20), whereas reaction time in men showed a slight and nonsignificant decrease. Conclusion: Risk factors for mefloquine-associated neuropsychiatric adverse events and concentration impairment are female gender, low BMI, and first-time use. The frequency of neuropsychiatric effects is highest in women with a BMI ≤20 kg m -2.

Adverse reactions, Body mass index, Mefloquine, Neuropsychiatric effects, Pharmaco-epidemiology,
British Journal of Clinical Pharmacology
Department of Psychiatry

van Riemsdijk, M.M, Sturkenboom, M.C.J.M, Ditters, J.M, Tulen, J.H.M, Ligthelm, R.J, Overbosch, D, & Stricker, B.H.Ch. (2004). Low body mass index is associated with an increased risk of neuropsychiatric adverse events and concentration impairment in women on mefloquine. British Journal of Clinical Pharmacology, 57(4), 506–512. doi:10.1046/j.1365-2125.2003.02035.x