Laxatives & Antidiarrhea Flashcards Preview

Pharmacology > Laxatives & Antidiarrhea > Flashcards

Flashcards in Laxatives & Antidiarrhea Deck (22)
Loading flashcards...
1

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

2

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 

3

Cathartics (stimulant laxatives) directly stimulate ____ to increase intestinal ____ 

Cathartics (stimulant laxatives) directly stimulate enteric nervous system to increase intestinal motility 

4

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) 

5

Castor Oil is contraindicated in ___ becauase it can cause ____ 

Castor Oil is contraindicated in pregnancy becauase it can cause uterine contractions  

6

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

7

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

8

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 

9

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 

10

Lactulose is metabolized by colonic bacteria and can cause severe ___ with ____ 

Lactulose is metabolized by colonic bacteria and can cause severe flatus with cramping 

11

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 

12

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

13

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 

14

Selective Mu-opioid receptor Antagonists (because opioids cause constipation) 

Alvimopan, Methylnaltrexone

15

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 

16

Anti-diarrhea Drugs 

  • Opioid Agonists
  • Octreotide (Somatostatin analog)
  • Bismuth subsalicylate 

17

Opioid Agonists, ____ and ____ inhibit ___ release and decrease gut ___

Contraindicated in ___ and patients with severe ___ 

Opioid Agonists, Loperamide and Diphenoxylate inhibit ACh release and decrease gut motility 

Contraindicated in children and patients with severe colitis 

18

____ has a low risk of addiction vs.

____ can lead to opioid dependence 

Loperamide has a Low risk of addiction vs.

Diphenoxylate can lead to opioid Dependence 

 

19

Octreotide is a ____ analog with ____ the half-life

Octreotide is a somatostatin analog with 30x the half-life

20

Octreotide treats secretory diarrhea due to ____, such as ___ and ___

and diarrhea caused by vagotomy, dumping syndrome, short bowel syndrome and AIDS

Octreotide treats secretory diarrhea due to neuroendocrine tumors, such as carcinoid and VIPoma

and diarrhea caused by vagotomy, dumping syndrome, short bowel syndrome and AIDS

21

Octreotide adverse affects 

  • steatorrhea and fat-soluble vitamin malabsorption d/t decreasing effect on pancreatic exocrine function
  • increased risk of gallstones d/t inhibition of GB contractility
    • acute cholecystitis 

22

Bismuth subsalicylate (BSS) controls ____ diarrhea via ____ fluid secretion in enteric tract 

BSS controls travelers diarrhea via decreasing fluid secretion in enteric tract