A COMPARATIVE STUDY OF SOME BRANDS OF TOLBUTAMIDE AVAILABLE IN CANADA. I. CLINICAL ASPECTS.

Two lots of brand-name and three lots of non-proprietary tolbutamide products, the latter having been reported to be clinically ineffective, were compared in a double-blind study in 22 diabetic patients. Every patient took each of the five brands for two weeks. The dose range was 1 to 2 g. per day and the dose was kept constant in each patient throughout the five test periods. Statistical analyses of fasting, mid-morning and mid-afternoon blood sugar levels, mid-morning and mid-afternoon blood tolbutamide levels and levels of tolbutamide and its metabolite in 24-hour urine did not show any significant differences among the five products except for better control of fasting blood-sugar levels by one brand, nor did clinical observations reveal any differences.