Laxatives Flashcards
Name 2 osmotic laxatives
Lactulose, movicol
Name 4 stimulant laxatives
Bisacodyl - Pure stimulant
Docusate sodium - Stimulant and softening
Glycerol suppository - Rectal stimulant
Senna - Pure stimulant
Name 2 bulk forming laxatives
Ispaghula hulk, methylcellulose
How do osmotic laxatives work?
Lactulose - Draws fluid in.
Macrogol (Movicol) - Retains the fluid in the large bowel that is already there.
What is lactulose particularly useful for?
Hepatic encephalopathy - Diarrhoea has a low pH that discourages growth of ammonia producing organisms.
How do stimulant laxatives work?
Increase intestinal mobility
When should you not use stimulant laxatives?
Bowel obstruction and acute colitis
What is an important side effect of stimulant laxatives?
Abdominal cramps
How do bulking agents work?
Increase faecal mass so stimulate peristalsis. They must be taken with fluid and take a few days to work
Contraindications of bulking agents
Dysphagia, GI obstruction, colonic atony, faecal impaction
What is prucalopride?
A serotonin agonist, a prokinetic used if standard laxatives dont work
What is the treatment algorithm for constipation?
- Lifestyle measures
- Bulk forming laxative
- Add/switch to osmotic laxative
- Add stimulant laxative is stools are soft but difficult to pass
- Add prucalopride
How do you treat opioid induced constipation?
Add osmotic and stimulant laxative, not a bulk forming laxative
Can laxatives be stopped suddenly?
No as will cause refractory constipation
