Polymorphic acetylation of sulfamethazine in a Nigerian (Yoruba) population.

1. Sulfamehtazine was administered orally to 165 Yoruba subjects (40 mg/kg body wt.). Free and acetylated sulfamethazine were determined in the 6 h urines. 2. The population frequency histogram for percentage of urinary acetylated sulfamethazine was bimodal, although not completely resolved. Slow acetylators constituted 45% of the population studied. 3. This Yoruba population did not differ statistically (P greater than 0.05) in this respect from the two major tribally distinct groups in Nigeria previously investigated.