Lactulose (Paediatric)
Brand names: Duphalac, Lactugal
Paediatric lactulose, an osmotic laxative, used in children for constipation and, at higher doses, in the management of hepatic encephalopathy.
ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.
Clinical monograph
How it works
A non-absorbed disaccharide that draws water into the bowel by osmosis to soften stool and promote peristalsis; colonic bacterial fermentation also acidifies the lumen, reducing ammonia absorption in hepatic encephalopathy.
Prescribing in practice
- Maintain adequate fluid intake during treatment, as lactulose works osmotically and the dose is titrated to produce soft, regular stools.
- Its effect is not immediate and may take a couple of days, so it is for regular rather than rapid relief.
- Use caution in lactose intolerance or galactosaemia and confirm paediatric dosing against a children's formulary.
Monitoring
Monitor stool frequency and consistency and the child's hydration, titrating the dose to response.
Counselling the patient
- Encourage plenty of fluids while taking lactulose.
- Explain it may take a day or two to work and the dose is adjusted to keep stools soft.
- Flatulence or cramps may occur initially and usually settle.
Evidence & guidelines
Lactulose is an established osmotic laxative for childhood constipation, used alongside other measures per NICE constipation guidance.
Reference: NICE NG90 (Constipation in Children); ESPGHAN Childhood Constipation Guidelines 2014; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).
Related
Curated clinical cross-links plus same-class fallbacks.