A.37. Drugs used in constipation (laxatives) and diarrhea. drugs promoting digestion. Pharmacology of liver and biliary tract. Flashcards
how are laxatives classified?
based on their mechanism of action:
- irritants and stimulants
- bulk-forming laxatives
- osmotic laxatives
- stool softeners
- lubricant laxatives
what are laxatives used for?
constipation
*may cause electrolyte imbalance when used chronically
what are sennoside and Bisacodyl?
irritants and stimulants
what classification does plant fiber belong to?
bulk-forming laxatives
list 3 osmotic laxatives
magnesium-sulphate
lactulose
glycerol
what is paraffin oil?
lubricant laxative
what does paraffin oil do?
facilitate the passage of hard stools
how paraffin oil should be taken?
orally in an upright position to avoid aspiration and potential lipoid pneumonia
what does Sennoside do?
irritant of the colonic wall to induce fluid secretion and colonic motility
how is Sennoside taken?
orally (causes evacuation of the bowels within 8-10 hours)
rectally (within minutes)
when do we give Sennoside?
- treatment for opioid-induced constipation
- evacuation of the bowel prior to surgery
- before invasive rectal/colonic examinations
what is the function of Bisacodyl
potent stimulant of the colon, acts on the nerve fibers in the colonic mucosa
when do we use Bisacodyl
- chronic constipation
- neurologic bowel dysfunction
- pre-operative preparartion
what are the adverse effects of Bisacodyl
abdominal cramps atonic colon (prolonged use) might damage the enteric protective coating
what are the SE of taking plant fibers
can cause obstruction and meteorism
what is the effect of plant fibers?
form gels in the large intestine –> causing water retention –>increased peristaltic activity
what is the effect of magnesium- sulfate as a laxative?
non-absorbable salt
hold water in the intestinal lumen by means of osmosis distended the bowel–> ↑ intestinal activity–> produces defecation in a few hours
what is Lactulose?
semisynthetic disaccharide sugar
cannot be hydrolyzed by intestinal enzymes
degraded by colonic bacteria into lactic, formic, and acetic acids.
↑ osmotic pressure –> fluid accumulation