Comparison of the effects of acarbose and voglibose in healthy subjects

Acarbose and voglibose are alpha-glucosidase inhibitors. Although the pharmacologic effects and incidence of abdominal adverse events associated with the two drugs have been reported to differ, no study has directly compared acarbose and voglibose. To compare the pharmacologic effects and gastrointestinal adverse events associated with the two drugs, a randomized, placebo-controlled, double-masked, fivefold crossover study was performed in 20 healthy male subjects. To assess the pharmacologic effects, plasma immunoreactive insulin (IRI), plasma glucose, and 24-hour urinary connecting-peptide immunoreactivity (CPR) excretion were measured. Although the postprandial increase in plasma glucose level was reduced significantly with both acarbose and voglibose, the rate of reduction was small. The maximum concentration (Cmax) and area under the plasma concentration-time curve (AUC) of plasma IRI after meals decreased significantly with all treatments except voglibose 0.3 mg compared with placebo. Overall, the Cmax and AUC of plasma IRI decreased more when subjects received acarbose than voglibose. Urinary CPR excretion decreased by 30.6% and 41.7%, respectively, in subjects who received acarbose 50 mg or 100 mg compared with the previous day when no drug was given, whereas the urinary CPR excretion did not decrease significantly with voglibose. There was no significant difference in the frequency of gastrointestinal adverse events between groups, including the placebo group. One-day administration of acarbose and voglibose at currently recommended clinical doses demonstrated that acarbose was more effective in sparing endogenous insulin secretion than was voglibose.