Self-reported adverse events associated with antimalarial chemoprophylaxis in peace corps volunteers.

Objectives: To determine adverse events associated with the use of antimalarial chemoprophylaxis in Peace Corps volunteers who have served in malaria-endemic countries 6 months or longer.

Methods: Survey of Peace Corps volunteers' adverse events associated with the use of antimalarial chemoprophylaxis between August 1, 2005 and July 31, 2006. Analyses were conducted in fall 2006.

Results: Two thousand seven hundred and one surveys were received (43% response rate) from volunteers in malaria-endemic countries, with 1,731 (64%) in country for 6 months or longer (average 19 months). Nearly two thirds (62%) reported at least one adverse event. Those on mefloquine reported the most neuropsychologic adverse events; those on doxycycline reported the most gastrointestinal as well as skin and vaginal adverse events. Nearly one quarter of respondents (23%) changed their chemoprophylaxis regimen due to adverse events. Severe adverse events were reported by 9% of respondents, and 1% reported being hospitalized.

Conclusions: Adverse events were frequently reported among volunteers using antimalarial medications for more than 6 months, but very few were severe or required hospitalization. In light of the large number of adverse events, having multiple drug regimens available for the long-term traveler may be one method of maintaining adherence to antimalarial chemoprophylaxis.