Laxatives- overview

A review of laxatives commonly used to treat constipation.

Osmotic laxatives-Soluble non absorbable compounds →enter stool →exert osmotic pressure ↑ fluid content of stools→ softening & ↑ ed bulk --> stimulation of peristalsis They increase the amount of water in the large bowel ( can draw fluid into the large bowel or retain the fluid that they are administered with ) Macrogols and lactulose also act as stool softeners First line osmotic laxatives are macrogols - consider using lactulose if macrogols not effective

Macrogols -inert polymers of ethylene glycol has electrolytes- so no net gain-loss of water Na or K+ sequester water in the intestinal lumen ↑ ed volume of faecal mass→ taggers peristalsis not absorbed→ excreted unaltered on faeces no change needed in CKD efficacy in treatment of constipation is well established can be used for chronic constipation, disimpaction ( refer to BNF )Usually safe and well tolerated , GI SEs most common- abdo pain ,diarrhea , vomiting , nausea , dyspepsia , distension , flatulence , anorectal discomfort ( due to expansion of contents of the GI tr & an ↑↑ in motility due to p Mild diarrhea - use lower dose Pregnancy-lack of safety data Can be...