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Osmotic Laxative·Gastrointestinal - Laxatives
Hepatic encephalopathy, chronic constipation
Max Dose
45 mL/day (Aperient)
Onset
1-2 Days
Flatulence
HIGH
Hepatic Enceph.
INDICATED
Overview
Synthetic, non-digestible sugar. Acts as a slow osmotic laxative. Crucially, it acts as a bacterial sink for ammonia in patients with liver failure.
Maximum Dose
Max 45 mL/day for constipation. (Doses in hepatic encephalopathy can exceed 90 mL/day to achieve target bowel actions).
Clinical Focus
Slow onset. Causes massive gas production and bloating. Often poorly tolerated for simple constipation compared to Movicol.
Bottom Line
Lactulose is a first-line osmotic laxative for constipation and hepatic encephalopathy, but causes significant bloating and flatulence and takes 24-48 hours to work.
Brand Names
Actilax, Duphalac
Oral Routes
Extremely sweet, viscous syrup (3.3 g/5 mL).
Prescribing & PBS
Over The Counter (OTC).
Primary
Hepatic encephalopathy, chronic constipation.
Clinical Place
The gold-standard baseline therapy for preventing and treating confusion in liver cirrhosis.