Diarrhea Flashcards
of attacks of acute diarrhea annually in world’s children
744 million to 1 billion
of deaths in children worldwide each year from diarrhea
4.5 million
Normal Pathophys vs Diarrhea Pathophys
- normally: GI tract absorbs water, electrolytes, carbs, fat, protein
- during acute diarrhea, water and electrolyte losses are isotonic losses
Secretory Diarrhea
- stimulating substance increases secretion and decreases absorption of water and electrolytes
- large stool volumes > 1L/day
Osmotic Diarrhea
- poorly absorbed substances increase retained intestinal fluids
- examples: malabsorption, lactose intolerance, lactulose
Exudative Diarrhea
-inflammation –> mucus, protein and blood excretion through the gut
Altered Intestinal Transit Diarrhea
3 mechanisms:
- reduction of contact time in small intestine
- premature gastric emptying
- bacterial overgrowth
Causes of Acute Gastroenteritis
- viral 30-40%
- bacterial or parasites 20-30%
- no identifiable source 40%
Diarrhea Infectious Organisms Common to US
- Shigella, Salmonella
- Campylobacter, Staph
- E coli (STEC), C diff
- Norwalk, Rotavirus
Antimicrobial Agent for Salmonella Infection
cipro or levofloxacin
alt: azithromycin
Antimicrobial Agent for Shigella Infection
cipro
alt: azithromycin
Antimicrobial Agent for C Diff Infection
metronidazole
alt: vancomycin
Antimicrobial Agent for STEC Infection
no treatment
Drugs That May Induce Diarrhea
- abx, laxatives
- colchicine (gout tx)
- digitalis, hydralazine, theophylline
- mannitol, sorbitol
- metformin (type 2 DM)
- misoprostol (PUD tx)
- quinidine
- thyroid products
Common Causes of Pseudomembranous Colitis
- complication of abx therapy
- most common w/ poorly absorbed abx, longer duration (>7 days), specific agents (eg clindamycin)
Signs of Pseudomembranous Colitis
- watery diarrhea
- fever
- abd pain and tenderness
- nausea
- bloody diarrhea
Pathophys of Pseudomembranous Colitis
-poor absorption of abx results in selective killing of normal GI flora –> overgrowth of bacteria including C diff
Pseudomembranous Colitis Treatment
- metronidazole 1st line
- vancomycin 2nd line (but 1st in severe infections)
Diarrhea Therapeutic Management Goals
- relieve sxs
- maintain hydration
- tx underlying causes
- maintain nutrition
4 Options for Therapeutic Management of Diarrhea
- no therapy
- dietary management
- oral rehydration solution
- pharmacologic management
Dietary Management for Diarrhea
- no solids or dairy x24 hours –> often effective for simple osmotic diarrhea
- if N/V present, mild, digestible, low-residue diet x24h
- breast feeding okay
- for chronic diarrhea, increase dietary bulk
Oral Rehydration Solutions MOA
- reduce mortality from diarrhea 30% to 3%
- based on isotonic loss of fluids during acute diarrhea
- sodium and glucose co-transport across proximal small intestine
- preserves the ability of gut lumen to continue to absorb sodium and co-transport glucose during diarrhea
What types of products are available for oral rehydration?
- rice-based solutions made at home: baby rice cereal, water, salt
- Pedialyte, Ceralyte
Adsorbents MOA
-adsorb nutrients, toxins, drugs and digestive juices
Adsorbents Generics
- calcium polycarbophil
- psyllium
- methylcellulose
Calcium Polycarbophil Trade Name
-Mitrolan
Adsorbents Efficacy
-effective in reducing fluid in the stool
Adsorbents Safety
-adsorptive capacity may actually worsen dehydration
Antiperistaltic/Antimotility MOA
block vagal tone and prolong GI transit time
Antiperistaltic/Antimotility Generics
- loperamide
- diphenoxylate + atropine
Loperamide Trade Name
Imodium
Dephenoxylate + Atropine Trade Name
Lomotil
Antiperistaltic/Antimotility Efficacy
-effective for tx of acute diarrhea
Antiperistaltic/Antimotility Safety
- atropine may result in anticholinergic toxicity (Esp in kids and elderly)
- potential for worsening traveler’s diarrhea
Antisecretory MOA
-block GI fluid flow
Antisecretory Generics
- bismuth subsalicylate
- octreotide (SQ or IV)
Bismuth Subsalicylate Trade Name
Pepto Bismol
Antisecretory Efficacy
moderately effective for traveler’s diarrhea
Antisecretory Safety
- potential for salicylate toxicity
- may darken tongue and stool
- do not use in kids w/ influenza or chicken pox due to risk of Reye’s syndrome
Probiotics MOA
-enhance normal GI tract flora
Probiotics Generic
lactobacillus acidophilus
Lactobacillus Trade Name
Lactinex
Probiotics Efficacy
-yogurt can provide relief of diarrhea due to lactose intolerance
Probiotics Safety
potential for introducing infection
