Substandard and falsified anti-tuberculosis drugs: a preliminary field analysis.

SETTING: Pharmacies in 19 cities in Angola, Brazil, China, Democratic Republic of Congo, Egypt, Ethiopia, Ghana, India (n = 3), Kenya, Nigeria, Russia, Rwanda, Thailand, Turkey, Uganda, United Republic of Tanzania and Zambia. OBJECTIVE: To assess the quality of the two main firstline anti-tuberculosis medicines, isoniazid and rifampicin, procured from private-sector pharmacies, to determine if substandard and falsified medicines are available and if they potentially contribute to drug resistance in cities in low- and middle-income countries. DESIGN: Local nationals procured 713 treatment packs from a selection of pharmacies in 19 cities. These samples were tested for quality using 1) thin-layer chromatography to analyze levels of active pharmaceutical ingredient (API), and 2) disintegration testing. RESULTS: Of 713 samples tested, 9.1% failed basic quality testing for requisite levels of API or disintegration. The failure rate was 16.6% in Africa, 10.1% in India, and 3.9% in other middle-income countries. CONCLUSIONS: Substandard and falsified drugs are readily available in the private marketplace and probably contribute to anti-tuberculosis drug resistance in low- and middle-income countries. This issue warrants further investigation through large-scale studies of drug quality in all markets.