Molecular epidemiology of malaria in Cameroon. XIX. Quality of antimalarial drugs used for self-medication.

Substandard and counterfeit pharmaceutical products are increasingly circulating and distributed around the world, in particular in less developed countries. These low-quality or counterfeit products often involve drugs that are in high demand for the prevention and treatment of highly prevalent diseases, such as antimalarial drugs in endemic countries. Self-medication for presumed malarial infections with drugs purchased from unofficial drug vendors is a common practice in Africa. The aim of the study was to investigate the quality of chloroquine, quinine, and sulfadoxine-pyrimethamine obtained from illegitimate sector in urban and rural areas in Cameroon and analyze the impact of these drugs on patients. We collected 284 samples of three antimalarial drugs from 132 different sources in 16 villages and cities throughout the country. We also collected antimalarial drugs that were used for self-medication by malaria-infected patients. Drug quality was assessed by a simple color reaction test and semi-quantitative thin-layer chromatography. Fifty (38%) of 133 chloroquine, 52 (74%) of 70 quinine, and 10 (12%) of 81 antifolates had either no active ingredient, an insufficient active ingredient, the wrong ingredient, or unknown ingredient(s). Self-medication with antimalarial drugs purchased from unofficial vendors is not a reliable strategy to diminish morbidity and mortality. These counterfeit drugs contribute to the spread of drug-resistant malaria parasites and may lead to increasing therapeutic failure and medical expense.