Responses to intravenous tolbutamide by Nigerians--a preliminary study.

Sixteen normal adult Nigerians (10 males and 6 females) were randomly selected for an intravenous tolbutamide test. The mean fall of blood sugar at 30 minutes corresponded closely to values observed in the Caucasians; however, there was a delay in the return of blood sugar to fasting level even at 240 minutes following tolbutamide administration. In spite of the low individual blood sugar levels attained during the study, no associated symptoms were observed. The possible contributory role of the counter-regulatory mechanisms in explaining the differences in the response to tolbutamide between the Nigerian and the Caucasian is discussed.