Therapeutic Intervention in the Lower GI tract Flashcards
Your patient has diarrhea.
Do you prescribe drugs as first-line tx?
- First, acutely treat with rehydration and electrolyte balance (glucose, salts)
- Reserve drugs for significant, persistant symptoms.
Anti-diarrheal tx:
list categories (6)
- Opioids (loperamide, diphenoxylate)
- Bulk forming and absorbents (fiber)
- Antibiotics
- Probiotics
- Bismuth subsalicylate (pepto-bismol)
- octreotide
What 2 narcotics are used to tx diarrhea?
- mech
- what’s the difference between them?
- Loperamide (Imodium)
- Diphenoxylate (Lomotil)
- both are Mu agonists
- Loperamide has no CNS penetration.
- Diphenoxylate has CNS penetration, so risk of abuse. Give atropine (this is why Lomotil has atropine in it)
What OTC GI drug has abuse potential, and how it this prevented?
Diphenoxylate (Lomotil OTC)
- opioid that has CNS penetration
- Lomotil OTC has atropine in it. Atropine is an abuse deterrent b/c of anticholinergic symptoms
Anti-diarrhea tx:
-what are the 2 bulk forming and absorbent treatments?
- Kaopectin (not bolded)
- Fiber
- absorb water, increase stool bulk
Loperamide
- mech
- tx what
(Imodium)
- opioid, mu agonist. No CNS penetration
- anti diarrhea
Diphenoxylate
- mech
- tx what
- Opioid, mu agonist
- anti diarrhea
- CNS penetration so give with atropine to prevent abuse
Fiber
-how does it prevent diarrhea? (2)
- increases stool bulk
- may bind toxins
Bismuth subsalicylate
- mech
- tx what
- mech still unknown, but thought to have anti secretory, anti-inflammatory, anti-microbial effects
- Prevention/tx of episodic diarrhea (eg traveler’s diarrhea)
Octreotide
- mech
- tx of what (2)
- somatostatin analog–inhibits hormone secretion from tumors of pancreas/GI tract
1. Tumor-related secretory diarrhea (eg Carcinoid syndrome)
2. also tx for variceal bleeding
Pt with carcinoid syndrome:
-Tx with what?
Octreotide
-somatostatin analog
Laxatives:
-general mechanisms (3)
- osmotic retention of luminal fluid
- decrease absorption/increase secretion of fluid
- alter motility
Fiber:
-divided into what types?
Fermented and Nonfermented fiber
Fermented fiber:
-mech as laxative (3)
- SCFA: prokinetic
- SCFA: trophic for endothelium
- Increase bacterial stool mass
Colonic bacteria produce SCFA (short chain fatty acids) by fermentation
Non-fermented fiber
-mech as laxative (2)
- retention of water
- increase stool bulk