Week 4 GI Part 3 Flashcards
(197 cards)
What are the main classes of antidiarrheal agents?
Opioid agonists, somatostatin analogues, adsorbents, bile acid sequestrants
What is diarrhea defined as?
The passage of ≥ 3 loose or liquid stools within 24 hours
Classify diarrhea based on duration.
- Acute: ≤ 2 weeks
- Persistent: > 2 weeks but < 4 weeks
- Chronic: ≥ 4 weeks
Classify diarrhea based on etiology and pathophysiology.
- Infectious diarrhea: Inflammatory, Noninflammatory
- Noninfectious diarrhea: Secretory, Osmotic, Malabsorption, Inflammatory, Altered motility
What are the general management strategies for diarrhea?
- Supportive care
- Antimicrobials for specific infectious etiologies (not routinely required)
- Antidiarrheal agents
What are the contraindications for using antidiarrheal agents?
- Diarrhea with fever
- Bloody or mucoid stool
- Diarrhea caused by Clostridioides difficile and Shigella
What is the mechanism of action for opioid agonists used as antidiarrheal agents?
Act on mu receptors in the myenteric and submucosal plexus to inhibit peristalsis, decrease secretion, and increase colonic transit time
Name two opioid agonists used for their antidiarrheal activity.
- Loperamide
- Diphenoxylate
What is the primary indication for loperamide?
Symptomatic relief in noninvasive diarrhea, mild traveler’s diarrhea, chronic diarrhea with inflammatory bowel disease (IBD)
What are common adverse effects of opioid agonists?
- Nausea
- Abdominal cramps
- Constipation
- Allergic reactions
What are the contraindications for using diphenoxylate?
- Invasive diarrhea
- Pseudomembranous colitis
What is the mechanism of action for somatostatin analogues?
Inhibit the release of serotonin and other GI peptides and hormones, decreasing intestinal fluid secretion and GI motility
What is a key indication for octreotide?
Secretory diarrhea caused by carcinoid syndrome, VIPoma, or gastrinoma
What are some adverse effects of somatostatin analogues?
- Nausea
- Abdominal pain
- Gallstone formation
- Steatorrhea
Name three medications classified as adsorbents.
- Bismuth subsalicylate
- Kaolin
- Pectin
What is the mechanism of action for adsorbents?
Coat the GI tract, allowing binding and elimination of infectious pathogens and toxins
What should bismuth subsalicylate not be used for?
- Allergy to salicylates
- GI bleed
What is the primary indication for bile acid sequestrants?
Bile acid malabsorption diarrhea
What is the mechanism of action for bile acid sequestrants?
Bind excess bile acids, forming insoluble compounds that decrease secretion of water and electrolytes
What is hepatitis D virus (HDV)?
A small enveloped, single-stranded RNA virus that requires hepatitis B virus for assembly and secretion
How is hepatitis D virus transmitted?
- Parenterally
- Unprotected sexual intercourse
- Perinatally
What is the clinical presentation of hepatitis D infection?
Classical viral hepatitis, often in conjunction with hepatitis B
What is the management for acute cases of hepatitis D?
Supportive care
What is the management for chronic cases of hepatitis D?
Pegylated interferon alfa (PEG-IFN-α)