Treatment of Traveler's Diarrhea
Azithromycin is the preferred first-line antibiotic for moderate-to-severe traveler's diarrhea, given as either a single 1-gram dose or 500 mg daily for 3 days, with loperamide as adjunctive therapy for non-bloody diarrhea. 1, 2
Severity-Based Treatment Algorithm
Mild Traveler's Diarrhea (Tolerable, Not Distressing)
- Do not use antibiotics for mild cases 1
- Start with loperamide monotherapy: 4 mg loading dose, then 2 mg after each loose stool (maximum 16 mg/day) 1, 2
- Bismuth subsalicylate is an alternative symptomatic treatment 1
- Ensure adequate hydration with oral rehydration solutions 2
Moderate Traveler's Diarrhea (Distressing, Interferes with Activities)
- Azithromycin is preferred: Single 1-gram dose OR 500 mg daily for 3 days 1, 2
- Loperamide can be used as monotherapy OR combined with antibiotics for faster relief 1, 2
- When combining loperamide with azithromycin, duration of illness decreases from 34 hours to 11 hours 3
- Alternative options include:
Severe Traveler's Diarrhea (Incapacitating, All Dysentery)
- Antibiotics are mandatory 1
- Azithromycin is the preferred agent: 1-gram single dose OR 500 mg daily for 3 days 1, 2
- Loperamide as adjunctive therapy reduces time to last unformed stool to less than half a day 1, 2
- Fluoroquinolones may be used for severe non-dysenteric cases, but azithromycin is superior due to global resistance patterns 1, 4
Critical Safety Warnings for Loperamide
Immediately discontinue loperamide if any of the following develop: 2, 4
- Fever
- Blood in stool (gross blood mixed with stool, not just streaks on toilet paper)
- Severe abdominal pain
- Symptoms persist beyond 48 hours
Never use loperamide in dysentery (bloody diarrhea with fever) 1, 2
Regional Considerations
Southeast Asia and India
- Azithromycin is mandatory first-line due to >90% fluoroquinolone resistance for Campylobacter 2, 4
- Do not use fluoroquinolones empirically in this region 2, 4
Mexico and Latin America
- Azithromycin remains preferred, though fluoroquinolone resistance is lower than Southeast Asia 6
- Combination therapy (azithromycin plus loperamide) reduces illness duration from 59 hours to approximately 1 hour 2
Other Destinations
When to Seek Medical Attention
Escalate care immediately if: 2
- No improvement within 24-48 hours despite self-treatment
- High fever with shaking chills develops
- Severe dehydration occurs
- Bloody diarrhea develops
- Symptoms persist beyond 14 days (consider protozoal infections, post-infectious IBS, or inflammatory bowel disease) 6
Obtain microbiological testing for: 2, 6
- Severe or persistent symptoms (>14 days)
- Bloody diarrhea
- Failure of empiric antibiotic therapy
- Immunocompromised patients
Special Populations
Children and Pregnant Women
HIV-Infected Persons
- Consider empiric fluoroquinolones before departure for self-treatment 2
- For severe immunosuppression, consider TMP-SMX, ampicillin, cefotaxime, ceftriaxone, or chloramphenicol 2
Important Caveats
- Routine antibiotic prophylaxis is strongly discouraged due to promotion of antimicrobial resistance and acquisition of multidrug-resistant bacteria 1, 2
- Rifaximin is only effective for non-invasive E. coli diarrhea and should not be used empirically in regions with high risk of invasive pathogens (Campylobacter, Shigella, Salmonella) 1, 5
- Single-dose antibiotic regimens are as effective as 3-day courses and improve compliance 2, 7
- The definition of dysentery is gross blood admixed with stool in the commode, not just streaks of blood on toilet paper (which likely represents hemorrhoids) 1