The objective of this study was to profile the user acceptability (self-reported adverse effects and compliance patterns) for mefloquine (250 mg weekly) and doxycycline (100 mg daily), which are currently the recommended malaria chemoprophylactic regimens for chloroquine resistant areas.
Travelers with return dates between November 1993 and October 1994 were enrolled in the study at a pretravel consultation at the Traveller's Medical and Vaccination Centres (TMVC) clinics in Adelaide and Melbourne, if they had been prescribed either mefloquine or doxycycline as the sole chemoprophylactic for their trip. The choice of antimalarial was decided after intensive discussions of the two regimens, contraindications, potential side effects, relative costs, and preferred efficacy. Questionnaires relating to self-reported morbidity and compliance levels were mailed to travelers approximately 2 weeks after their return to Australia.
Two hundred and eighty-five travelers (60.0% female, 40.0% male) used mefloquine for a mean of 6.5 tablets. Overall, 51.2% of users experienced illness or symptoms while taking the medication. Symptoms attributed by travelers to mefloquine, and usually temporally related to it, were reported by 37.9% of all users. Adverse events with significant impact on activities were reported by 14.6% of all female users and 6.1% of all male users. On return, 78.2% reported complete compliance with the mefloquine regimen overall; 6.3% stopped the drug specifically because of adverse effects, which were attributed to the drug and which were interfering with daily activities (8.8% females and 2.6% males).
Three hundred and eighty-three travelers (47.8% female and 52.2% male) used doxycycline for a mean of 27.5 daily doses. Health problems were experienced by 36.8% of travelers and 21.4% overall experienced what they considered to be adverse drug effects. Troublesome effects were reported by 8.7% of all females and 4.5% males. Complete compliance with the regimen was reported by 68.1% of users. Overall, 5.7% stopped early because of adverse effects, which were attributed to the drug and which were interfering with daily activities (6.6% females, 5.0% males).
Drug morbidity must be a consideration when prescribing antimalarial drugs. Noted in this study was the finding of a greater number of adverse events reported by females, particularly for mefloquine. The reasons for this difference between males and females will need to be further explored.