Diarrhea Medications

1. Rehydration (First Priority)

• In children: Pedialyte and similar commercial ORS solutions
• Zinc supplementation (WHO recommendation especially in children) shortens diarrhea duration and severity

2. Symptomatic (Antimotility) Agents

Caution: Antimotility drugs are contraindicated in C. difficile infection, bloody diarrhea, or if Shiga toxin-producing E. coli is suspected (increases risk of hemolytic-uremic syndrome, especially in children/elderly).

3. Adsorbents and Intestinal-Acting Agents

• Bismuth subsalicylate (Pepto-Bismol) - has antibacterial properties; useful for traveler's diarrhea and mild acute diarrhea
• Kaolin-pectin preparations - bind toxins and add bulk to stool
• Bile acid-binding resins (e.g., cholestyramine) - used specifically for bile acid-induced diarrhea (e.g., post-cholecystectomy)

4. Secretory Diarrhea

• Octreotide - a somatostatin analog; useful for hormone-mediated secretory diarrhea (e.g., carcinoid, VIPoma) and refractory cases

5. Antibiotics (for infectious causes)

6. Special Populations

• HIV/advanced immunocompromise: Diarrhea may be caused by Cryptosporidium, CMV, MAI, or C. difficile - requires targeted therapy based on identified pathogen
• Children: Avoid loperamide in children under 2; focus on ORS and zinc

Key "Do Not Use" Rules

• Do NOT use antidiarrheals in bloody diarrhea or high fever (possible invasive infection)
• Do NOT use antidiarrheals in suspected E. coli O157:H7 (risk of HUS)
• Do NOT use antibiotics empirically in mild, self-limiting diarrhea

Food Poisoning - Medications and Treatment

Step 1: Rehydration (ALWAYS First)

• Mild-moderate: Oral Rehydration Salts (ORS), water, clear broths, electrolyte drinks (Pedialyte, Gatorade)
• Severe dehydration: IV fluids (normal saline or Ringer's lactate)
• Avoid high-sugar drinks (worsens fluid loss)

Step 2: Symptomatic Medications (OTC)

Important: Antimotility drugs (loperamide) alone should be avoided in invasive bacterial food poisoning (Salmonella, Shigella, Campylobacter) - they prolong fever, increase bacteremia, and can promote the carrier state. However, loperamide is safe when given together with antibiotics.

Step 3: Antibiotics (Cause-Specific)

• Severe illness with high fever or systemic symptoms
• Immunocompromised patients, elderly, infants
• Specific identified pathogens

Step 4: Special Scenarios

When to See a Doctor Urgently

• Bloody stools
• High fever (>38.5°C / 101.3°F)
• Inability to keep fluids down for >24 hours
• Signs of dehydration (no urination, dizziness, dry mouth)
• Symptoms lasting >3 days
• Neurological symptoms (numbness, blurred vision, weakness) - possible botulism

Broad-Spectrum Antibiotics for Food Poisoning

The Top 3 Broad-Spectrum Options

• Levofloxacin - 500 mg once daily x 3 days
• Ofloxacin / Norfloxacin - similar spectrum to ciprofloxacin

Which One to Choose?

Important Warnings

• Avoid all antibiotics in suspected E. coli O157:H7 (STEC) - bloody diarrhea without fever - risk of triggering Hemolytic Uremic Syndrome (HUS), especially in children
• Avoid other antibiotics in C. difficile - use oral vancomycin or fidaxomicin instead
• TMP-SMX (Bactrim) is no longer recommended for food poisoning - widespread resistance worldwide
• Azithromycin has replaced ciprofloxacin as the global preferred first-line empiric agent due to rising fluoroquinolone resistance

Quick Dosing Summary

Azithromycin:  1000 mg single dose PO  (adult)
               OR 500 mg once daily x 3 days

Ciprofloxacin: 500 mg twice daily x 3-5 days PO
               (400 mg q12h IV if hospitalized)

Ceftriaxone:   1-2 g once daily IV (severe/hospitalized)

Rifaximin:     200 mg three times daily x 3 days
               (mild, non-invasive cases only)

Note: Antibiotics are only indicated when food poisoning is moderate-to-severe, has systemic symptoms (high fever, bloodydiarrhea, prolonged illness), or the patient is high-risk (elderly, immunocompromised, infants). Mild self-limiting cases resolve with ORS and rest alone.