Constipation

Question 1

What are the 5 classes of laxatives?

Answer 1

Bulking agents
Faecal softeners and lubricants
Osmotic laxatives (saline, disaccharide, polyols, macrogols)
Stimulant laxatives
Other

Question 2

Bulking agents

Answer 2

Bran

Psyllium

Question 3

How do bulking agents work?

Answer 3

Greater faecal water retention

increased normal reflex bowel activity

Question 4

How do faecal softeners and lubricants work?

Answer 4

Detergents (enhance mixture of water into faeces)

OR lubricant mineral oil (e.g. liquid paraffin)

Question 5

Docusate

Answer 5

Faecal softener and lubricants

Question 6

Magnesium sulphate (Epsom salts)

Answer 6

Saline laxative

Question 7

Lactulose

Answer 7

Disaccharide

Question 8

Sorbitol

Answer 8

Polyol

Question 9

Bisacodyl

Answer 9

Stimulant laxative

Question 10

Senna

Answer 10

Stimulant laxative

Question 11

Metoclopromide

Answer 11

Anti-emetic drug (D2-receptor antagonist)

Also 5HT4-receptor agonist which together with inhibition of D2 increases motility of GIT by increasing ACh release