What is the most effective antibiotic for treating Traveler's Diarrhea (TD)?

From the Guidelines

Azithromycin is the most effective antibiotic for treating Traveler's Diarrhea (TD), particularly in cases of dysentery or acute watery diarrhea with greater than mild fever, due to its high efficacy and low resistance rates compared to other antibiotics, as demonstrated in a high-level evidence study published in the Journal of Travel Medicine in 2017 1.

Key Considerations

When selecting an antibiotic for TD, several factors should be considered, including:

• The likelihood of treatment efficacy and rapidity of response
• Regional patterns of probable target pathogens and their antimicrobial resistance
• Safety and tolerance profile of the antibiotic
• Simplicity of treatment regimen and patient adherence
• Cost

Antibiotic Options

• Azithromycin: a first-line agent for TD, especially in areas with high rates of fluoroquinolone-resistant Campylobacter, with a recommended dose of 1000 mg as a single dose or 500 mg daily for 3 days 1
• Fluoroquinolones (FQs): may be considered in areas with low resistance rates, but their use is limited by concerns about reduced benefit due to resistance and potential adverse effects, such as Achilles tendon rupture and C. difficile infection 1
• Rifaximin: a nonabsorbable antibiotic with comparable efficacy to FQs in non-invasive TD caused by diarrheagenic E. coli, but less effective for invasive pathogens 1

Treatment Approach

• Antibiotics should be reserved for moderate to severe cases of TD with fever or bloody diarrhea
• Patients should stay hydrated with oral rehydration solutions or clear fluids and consider taking loperamide (Imodium) for symptom relief
• Prevention through careful food and water choices remains the best strategy for avoiding TD

Important Notes

• Azithromycin has been shown to be superior to levofloxacin in achieving clinical cure in Thailand, where FQ-resistant Campylobacter rates exceed 90% 1
• FQ-resistant travel-associated and domestic Campylobacter cases have been increasingly reported in industrialized countries, supporting the use of azithromycin as first-line therapy for dysentery 1

From the Research

Effective Antibiotics for Traveler's Diarrhea

• The most effective antibiotic for treating Traveler's Diarrhea (TD) is azithromycin, especially in Asia where Campylobacter is common 2.
• Fluoroquinolone antibiotics, such as levofloxacin, are also effective in Latin America and Africa where ETEC is predominant 2.
• A study comparing single-dose azithromycin, levofloxacin, and rifaximin with loperamide found that all three regimens were comparable for treatment of acute watery diarrhea 3.
• Another study found that single-dose treatment with azithromycin (1000 mg) and loperamide was as effective as single-dose treatment with levofloxacin (500 mg) and loperamide for noninflammatory diarrhea 4.

Comparison of Antibiotic Regimens

• A randomized, double-blind trial comparing single-dose and 3-day azithromycin-based regimens with a 3-day levofloxacin regimen found that single-dose azithromycin had the highest cure rate at 72 hours after treatment initiation 5.
• The same study found that single-dose azithromycin was associated with the shortest median time to last unformed stool (TLUS) 5.
• A study reviewing medications for the prevention and treatment of traveler's diarrhea found that azithromycin is the drug of choice, especially in Asia where Campylobacter is common 2.

Adverse Events

• Azithromycin use was associated with more nausea in the 30 minutes after dosing compared to levofloxacin 4, 5.
• However, the nausea associated with azithromycin was mild and self-limited 5.