Osmotic Laxatives
Examples
Indications
- Constipation
- Bowel preparation prior to surgery
- Hepatic Encephalopathy (lactulose)
Contraindications
- Intestinal Obstruction/perforation
- Paralytic ileus (Laxido)
- Galactosaemia (Lactulose)
Cautions
- Heart Failure
- Ascites
- Electrolyte disturbance
- Lactose Intolerance (Lactulose)
Mechanism
These medicines are composed of osmotically active substances (eg sugar) that are not digested or absorbed so remain in the intestinal lumen and hold water in the stool to provoke peristalsis and keep faecal bulk volume.
In hepatic encephalopathy, Lactulose is used to reduce ammonia absorption. Ammonia has a key role in the pathogenesis of hepatic encephalopathy.
Administration
Oral
Adverse Reactions
- Abdominal discomfort
- Cramps
- Flatulence
- Nausea
- Vomiting
- Electrolyte imbalance
Interactions
May increase the effects of warfarin
Education
Nil of note
Pharmacokinetics
Nil of note
