Determination of the isoniazid acetylator phenotype in a West African population.

The concentration of isoniazid in plasma after an oral dose of 10 mg/kg was estimated in 120 Nigerians (39 normal, 81 tuberculous). The concentrations were bimodally distributed giving a good discrimination between slow and rapid acetylators. The proportion of rapid to slow acetylators in the whole group was 60:40. This is similar to the results of the only other study of acetylator phenotype in West Africans.