Laxatives & Antidiarrhea Flashcards
constipation is stool frequency less than ___ / week
1st line strategy?
why is over-the-counter laxative use not 1st line
constipation is stool frequency less than 3/ week
1st line strategy?
lifestyle modifications (increased dietary fiber, physical activity)
why is over-the-counter laxative use not 1st line?
may become dependent or may abuse them in weight loss attempts
list bulk-forming laxatives
- Methylcellulose
- Psyllium
- Bran
- absorb water to form bulky, soft jelly that distends the colon to promote peristalsis
- contraindicated in immobile patients and with long term opioid use
Cathartics (stimulant laxatives) directly stimulate ____ to increase intestinal ____
Cathartics (stimulant laxatives) directly stimulate enteric nervous system to increase intestinal motility
describe the Cathartics
-
Castor oil: broken down to ricinoleic acid in SI
- contraindicated in pregnancy (may cause uterine contractions)
- Bisacodyl: acts on colon, minimal systemic absorption, safe for acute and long-term use
- Senna: chronic use causes melanosis coli (harmless brown pigmentation of colonic mucosa that is unrelated to colon cancer risk)
Castor Oil is contraindicated in ___ becauase it can cause ____
Castor Oil is contraindicated in pregnancy becauase it can cause uterine contractions
chronic use of senna causes ____, a harmless brown pigmentation of colonic mucosa that is unrelated to colon cancer risk
chronic use of senna causes melanosis coli, a harmless brown pigmentation of colonic mucosa that is unrelated to colon cancer risk
stool softeners, ____ and ____, function as ____ allowing water to penetrate and soften formed stool in bowel
stool softeners, Docusate and Glycerin, function as surfactants allowing water to penetrate and soften formed stool in bowel
Lubricant Laxative, ____, coats fecal material preventing water ____
Do not give with ____, as it negates laxative effect
Lubricant Laxative, Mineral oil, coats fecal material preventing water reabsorption
Do not give with docusate, as it negates laxative effect
Osmotic Laxatives are nonabsorbable ___ or ____ exerting osmotic ___ to retain water in intestinal lumen
list them
Osmotic Laxatives are nonabsorbable sugars or salts exerting osmotic pull to retain water in intestinal lumen
Lactulose
Magnesium Salts(mag. hydroxide, mag. sulfate)
Polyethylene Glycol
Lactulose is metabolized by colonic bacteria and can cause severe ___ with ____
Lactulose is metabolized by colonic bacteria and can cause severe flatus with cramping
Do not use magnesium salts long term in patients with ____ b/c it may cause ____
Do not use magnesium salts long term in patients with renal insufficiency b/c it may cause hypermagnesemia
Polyethylene Glycol (PEG) generates high ____ in gut lumen.
It is commonly used for complete bowel prep before ____
It is the referred management for _____
Polyethylene Glycol (PEG) generates high osmotic pressures in gut lumen.
It is commonly used for complete bowel prep before GI endoscopic procedures
It is the referred management for chronic constipation
Lubiprostone stimulates _____ of SI, increasing Cl- secretion which stimulates intestinal ___
Used for chronic constipation and ___ pts with constipation
AE: ___
contraindicated in ____
Lubiprostone stimulates type 2 chloride channel of SI, increasing Cl- secretion which stimulates intestinal mobility
Used for chronic constipation and IBD pts with constipation
AE: diarrhea
contraindicated in children
Selective Mu-opioid receptor Antagonists (because opioids cause constipation)
Alvimopan, Methylnaltrexone
Alvimopan, methylnaltrexone do not ____ so they don’t ___ opioid effects - they only act on the ___ to maintain normal ___
Alvimopan, methylnaltrexone do not cross BBB so they don’t block opioid effects - they only act on the gut to maintain normal motility
