Laxative Selection for Patients on GLP-1 Analogues

Introduction to Laxative Treatment

For patients with type 2 diabetes taking GLP-1 receptor agonists who develop constipation, the American Gastroenterological Association recommends osmotic laxatives—specifically polyethylene glycol (PEG), lactulose, or lactitol—as the first-line pharmacological treatment, with bisacodyl or sodium picosulfate reserved for short-term or rescue use 1

Lactulose is dosed at 10-20 g (15-30 mL or 1-2 packets) daily, with potential increase to 40 g (60 mL or 2-4 packets) daily if needed, and does not lead to increased blood sugar levels in patients with type 2 diabetes who are not insulin-dependent 1
The main limitation of lactulose is dose-dependent bloating and flatulence, which may limit tolerability in some patients 1

Bisacodyl or sodium picosulfate should be used for short-term treatment (≤4 weeks of daily use) or as rescue therapy when osmotic laxatives are insufficient, leading to large increases in complete spontaneous bowel movements (CSBMs) per week (mean difference 2.54, 95% CI 1.07-4.01) and spontaneous bowel movements (SBMs) per week (mean difference 4.04, 95% CI 2.37-5.71) 1
Start at a lower dose and titrate upward as tolerated to minimize abdominal cramping and diarrhea, with current evidence supporting primarily short-term or intermittent use 1