Plasmodium falciparum Malaria and Atovaquone-Proguanil Treatment Failure
We noticed overrepresentation of atovaquone-proguanil therapeutic failures among Plasmodium falciparum-infected travelers weighing >100 kg. We report here 1 of these cases, which was not due to resistant parasites or impaired drug bioavailability. The follow-up of such patients should be strengthened.

Fewer than 25 cases of falciparum malaria that failed to respond to atovaquone-proguanil (A-P) have been noted in published articles since the 1996 registration of Malarone (GlaxoSmithKline, Marly-le-Roi, France). Well-documented cases that were not attributed to suboptimal dosage or impaired bioavailability essentially due to vomiting, diarrhea, or both, showed atovaquone-resistant parasites in the recrudescent isolate, with Y268S or Y268N cytochrome b mutations. We report the case of treatment failure that was not due to resistant parasites or impaired drug bioavailability.