[Assessment of the efficacy of antimalarial drugs in Tarapacá, in the Colombian Amazon basin]

[[[ Introduction: ]]] The current antimalarial drug policy in Colombia has been based on studies conducted in Antioquia and the Pacific Coast. However, the efficacy of antimalarial drugs in other endemic regions is unknown. [[[ Objective: ]]] The therapeutic efficacy of three monotherapies was assessed: amodiaquine and sulfadoxine/pyrimethamine for uncomplicated Plasmodium falciparum malaria, and chloroquine for Plasmodium vivax malaria in the municipality of Tarapacá, located in the Colombian province of Amazonas. [[[ Materials and methods: ]]] Treatment was supervised and clinical/parasitological follow-up was undertaken through a 28-day period following to World Health Organization standard protocols for subjects with a single P. falciparum or P. vivax infection. [[[ Results: ]]] Due to a decrease in malaria transmission at the time of the study, the sample size was very small. The treatment failed for two subjects who received amodiaquine, and treatment with sulfadoxine/pyrimethamine was discontinued due to a high frequency of therapeutic failures (7/8). Most subjects (18/20) with P. vivax infections showed an adequate therapeutic response. [[[ Conclusions: ]]] The use of sulfadoxine/pyrimethamine in Tarapacá, and possibly in the Amazon region of Colombia, needs to be reviewed. Therapeutic efficacy studies in other endemic areas in the Amazon and Orinoco regions in Colombia are desirable but not feasible. Alternative methods such as in vitro assays or detection of molecular markers for resistance in the parasite can provide a basis for decisions concerning antimalarial drug policy for the Amazon and Orinoco regions in Colombia.