Managing Diarrhoea, Constipation and IBS Flashcards
name some opioids used for diarrhoea
codeine phosphate,
diphenoxylate,
loperamide (in immodium)
how do opioids work in teh gut to treat diarrhoea?
agonist of the mu-opioid receptors in the gut. inhibit propulsive movements of the bowel and prolong transit time which also provides an opportuinty for enhanced fluid absorption whcih may harden stool
why are opioids used for diarrhoea not addictive?
they do not cross the blood-brain barrier
name some bulk-forming laxatives
bran,
isphaghula husk,
methylcellulose,
sterculia
why would bulk forming laxatives not be good for someone with acute diarrhoea?
full effect takes a few days so you may need something that acts quicker.
what type of laxative are macrogols?
osmotic laxative
what type of laxative is lactulose?
osmotic
how do osmotic laxatives work?
draw water back into stool - need to keep patients hydrated for it to work
why are osmotic laxatives given to patients with liver failure?
they increase gut transit time whcih reduces ammonia absorption and acidifies the stool which inhibits proliferation of ammonia-producing bacteria and this can prevent hepatic encephalopathy
when are osmotic laxatives contraindicated and why?
intestinal obstruction due to increased risk of perforation
give some examples of stimulant laxatives (3)
bisacodyl
docusate sodium
senna
how do stimulant laxatives work
increase bowel movements and secretion of water and electrolytes from colonic mucosa
which stimulant laxative would you use if you wanted rapid action in 15-30 minutes?
bisacodyl
which stimulant laxative is a powerful irritant often given orally to prepare the bowel for surgery or colonoscopy because it acts in <6hrs?
sodium picosulphate
what type of laxative is docusate sodium?
faecal softener