Lactulose
An osmotic laxative. For hepatic encephalopathy, titrate to 2–3 soft stools a day.
On this page
Uses
- Constipation.
- Hepatic encephalopathy (treatment and prevention).
Adult dose
| Indication | Dose |
|---|---|
| Constipation | 15 mL twice daily, adjusted |
| Hepatic encephalopathy | 20–30 mL 2–3 times daily, adjusted to produce 2–3 soft stools a day; via NG tube or as an enema if drowsy |
Children's dose (constipation)
1–4 years 2.5–10 mL daily; 5–17 years 5–20 mL daily, in 1–2 doses.
Side effects and cautions
- Bloating, wind, cramps; diarrhoea and dehydration if overdosed.
Frequently asked questions
What is the target with lactulose in hepatic encephalopathy?
Two to three soft stools a day.
Used in these guides
Sources
Doses on this page are typical doses from the sources above. Always confirm with a current drug reference, the product leaflet and your hospital protocol, especially in children, pregnancy and kidney or liver disease.
For FCPS Part 1
Revising for FCPS Part 1? Lactulose is covered in our textbook chapter Gastrointestinal drugs, with practice MCQs.