2 Lower GI pharm [3] Flashcards
1st choice fiber/bulk forming ____ approximate physiological mechnism by ______ and _____ via absorption of water and subsequent bulk expansion. We must use ______ since they can interact with other drugs.
psyllium.
facilitate passage and stimulate peristalsis
space dosing
Docusate
Mineral oil
surfactant: stool softener with PREVENTION as primary role
Lubricant: coats fecal contents to prevent colonic absorption of fecal water
saline/Osmotic cathartics
- example
non-absorbable ions → osmotic retention of intestinal water → increased peristalsis
polyethylene glycol (miralax): high volume for BOWEL CLEANSING prior to procedures (prevent net transfer of electrolytes into lumen or small volume for CONSTIPATION - can lead to electrolyte depletion in prolonged use.
If fiber/saline fails, you can use ________.
example.
stimulant-irritant laxatives
Bisacodyl: induce peristalsis by inducing low grade inflammation in the bowel → promote accumulation of water and electrolytes and stimulate intestinal motility
most widely abused class of laxatives
bisacodyl
- dangerous side effects: electrolyte/fluid deficiencies, severe cramping
Castor oil acts where in the GI? to do what?
acts in the small intestine → stimulate fluid/electrolyte secretion and speed intestinal transit
Loperimide
antidiarrheal/opioid (like polycarbophil)
- can help with cholera toxin
(only block downstream effect by decreasing secretion, not affecting the increase in cAMP happening upstream.
- effective for travelers diarrhea
polycarbophil
antidiarrheal/opiod (like loperimide)
safe for both diarrhea and constipation
Bismuth subsalicylate (pepto bismol)
absorbent agent
- absorb toxins that cause irritation, take after each loose bowel movement until diarrhea is controlled
- avoid in children under 12 due to increased risk for Reyes syndrome
