First-lineDuphalac / Lactugal
Lactulose
Osmotic disaccharide laxative
First-line pregnancy constipation — non-absorbed, safe throughout.
Oral
First-line for
- Constipation in pregnancy and puerperium
- Hepatic encephalopathy
Mechanism
Non-absorbed disaccharide → osmotic water retention in colon + bacterial fermentation acidifies lumen and softens stool.
"Lactulose = liquid, laxative, low-risk"
- Takes 24–48 h to work
- Bloating and flatulence common
- Adjust dose to soft daily stool
Dosing
- Adults
- 15 mL BD, titrate to effect
Contraindications
- AbsoluteGalactosaemia
- AbsoluteIntestinal obstruction
Side effects
- Flatulence, bloating (usually settles in a week)
- Abdominal cramps
- Diarrhoea if over-dosed
Fetal & maternal notes
- • Not absorbed → no fetal exposure
- • Compatible with breastfeeding
Key interactions
Other laxatives
CautionAdditive diarrhoea/hypokalaemia
Clinical pearls
- 💡 Encourage fluids + fibre first
- 💡 Titrate over the first week to minimise bloating
Content last reviewed: REPLACE_ME (e.g. 2026-07)
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