Racial differences in drug metabolizing ability: a study with antipyrine in the Sudan.

The kinetic disposition of antipyrine following oral administration of 1,200 mg has been investigated in 11 normal Sudanese subjects living in Sudan, 9 Sudanese subjects living in England for at least 2 yr, and 19 normal English subjects living in England. Sudanese subjects living in Sudan had significantly lower mean antipyrine clearance and higher volume of distribution than the English group (-28% and +30%, respectively). There was no significant difference for antipyrine clearance between English and Sudanese subjects living in England, but the volume of distribution of antipyrine was higher (16%) in the Sudanese subjects. The mean half-lives of the three groups differed significantly. We conclude that differences in disposition of antipyrine between native English and Sudanese populations was predominantly due to environmental factors.