Acarbose is added to a diabetic patient's regimen. Two weeks later he complains of excessive flatulence and bloating. Which mechanism of acarbose directly explains these gastrointestinal side effects?

• A It chelates dietary carbohydrates in the gastric lumen
• B It stimulates cholecystokinin release, increasing gallbladder contraction
• C It reduces gastric emptying through GLP-1 potentiation
• D It inhibits alpha-glucosidase in the small intestinal brush border, causing carbohydrate fermentation by colonic bacteria ✓

Explanation

Acarbose inhibits alpha-glucosidase enzymes on the small intestinal brush border, delaying carbohydrate digestion and absorption. Undigested carbohydrates reach the colon where bacterial fermentation produces gas, causing flatulence, bloating, and diarrhea. These dose-related GI effects are the main reason for poor tolerability and discontinuation.

Reference: Goodman and Gilman's The Pharmacological Basis of Therapeutics, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.