Agents Affecting GI Motility Flashcards
Which antidiarrheal coats the lining of the GI tract and soothes irritation, preventing stimulation of local reflexes that cause excessive GI activity and diarrhea?
Bismuth subsalicylate (Pepto-Bismol)
AE of Bismuth subsalicylate (Pepto-Bismol):
Black coating on the tongue
Patients with what type of failure should avoid taking Bismuth subsalicylate (Pepto-Bismol)?
Renal failure
Which antidiarrheal is a Mu agonist that does not cross the BBB, slows peristalsis and allows increased time for absorption of fluid and electrolytes?
Loperamide (Imodium)
Because of Loperamide (Imodium)’s action at the Mu receptor what might a patient develop?
Physical dpendence
AE of Loperamide (Imodium):
N/V, abdominal pain, bloating
Opium derivatives (paregoric) do what to prevent diarrhea?
Inhibit peristalsis
How do bulk forming laxatives like Metamucil and FiberCon work?
- Causes the fecal matter to increase in bulk
- Increase GI motility by increasing fluid in the GI tract
- Stimulate stretch receptors
What type of laxatives are Senna (Senokot), Bisacodyl (Dulcolox), Castor oil, and mineral oil?
Stimulant laxatives
How do stimulant laxatives work?
-Direct action on the intestinal mucosa
-Stimulate myenteric plexus
Alter water and electrolyte secretions
How do the onset of action between Senna (Senokot) and Bisacodyl (Dulcolox) differ?
Senna: 6-10hrs
Dulcolox: 15-60mins
Castor oil: type of laxative, onset of action, when CI
Stimulant
2-6hrs
Pregnant women
Which stimulant laxative lines the GI tract, prevents absorption of water and electrolytes, and has an onset of action of 6-8hrs?
Mineral oil
Which type of laxatives work by retaining water in the the intestinal lumen, increasing intraluminal pressure, and causing CCK release?
Saline and Osmotic laxatives
When are saline and osmotic laxatives used?
Prep for surgery/colonoscopy
Evacuate bowel in ~3hrs
Name some saline and osmotic laxatives:
Magnesium salts (Epsom salt) Milk of Magnesia Magnesium hydroxide Magnesium citrate Sodium phosphate (enema) Lactulose Glycerin Sorbitol
How do surfactants/stool softeners work and examples?
-Detergent activity
-Facilitates water to soften stool
Docusate sodium (Colace)
Docusate calcium (Surfak)
When are surfactant/stool softeners often used and in combo with what other drug?
Post-op
In combination with Senna (stimulant lax)
What condition is Linaclotide (Linzess) used for and how does it work?
IBS with constipation
Stimulates intestinal fluid secretion and transit
(long-term risks unknown)
What condition is Lubiprostone used for and how does it work?
IBS with constipation
Locally acting chloride channel activated that enhances chloride-rich intestinal fluid secretion
