Is it appropriate to obtain prescriptions for azithromycin and ciprofloxacin as prophylaxis for travelers' diarrhea while I travel to Patagonia in a few weeks, and what are their indications?

Antibiotic Prescriptions for Traveler's Diarrhea to Patagonia

You should NOT obtain prescriptions for azithromycin and ciprofloxacin as prophylaxis for your trip to Patagonia—routine antibiotic prophylaxis is strongly discouraged due to promotion of multidrug-resistant bacteria, risk of C. difficile infection, and disruption of gut microbiome. 1 However, you should carry azithromycin (not ciprofloxacin) for empiric self-treatment of moderate-to-severe diarrhea if it develops during travel. 1

What You Should Actually Pack

Carry these medications for self-treatment, not prophylaxis:

• Azithromycin 500 mg tablets (prescription needed): For moderate-to-severe diarrhea with fever, blood in stool, or incapacitating symptoms 1
• Loperamide 2 mg tablets (over-the-counter): For immediate symptomatic relief in mild cases 1
• Oral rehydration salt packets (over-the-counter): For maintaining hydration 1
• Thermometer: To monitor for fever ≥38.5°C 1

Why Azithromycin, Not Ciprofloxacin?

Azithromycin is the preferred first-line agent for traveler's diarrhea globally due to increasing fluoroquinolone resistance. 1 While Patagonia is not a high-resistance region like Southeast Asia, azithromycin remains superior because:

• It covers all major bacterial pathogens including Campylobacter, Shigella, Salmonella, and E. coli 2
• Fluoroquinolone resistance is increasing globally, not just in Asia 1
• The FDA has issued safety warnings regarding disabling peripheral neuropathy, tendon rupture, and CNS effects with fluoroquinolones 1
• Azithromycin is safer for all travelers, including pregnant women and children 1

When to Use Azithromycin

Initiate azithromycin immediately if you develop:

• Moderate diarrhea: Distressing symptoms that interfere with planned activities 1
• Severe diarrhea: Incapacitating symptoms preventing normal function 1
• Fever ≥38.5°C with diarrhea 3, 1
• Blood in stool 3, 2
• Severe abdominal pain with diarrhea 1

Do NOT use antibiotics for mild diarrhea (tolerable symptoms that don't significantly disrupt activities)—use loperamide and hydration only. 1

Dosing Instructions

For azithromycin, choose one of these regimens:

• Single 1000 mg dose (preferred for better compliance) 1, 2
• Alternative: 500 mg daily for 3 days (equally effective) 1, 2

For loperamide (mild cases only):

• Initial dose: 4 mg, then 2 mg after each loose stool 1
• Maximum: 16 mg in 24 hours 1
• Stop immediately if fever, blood in stool, or severe abdominal pain develops 1, 4

Combination Therapy for Faster Relief

If you use azithromycin for moderate-to-severe diarrhea, combine it with loperamide for maximum efficacy. 1, 5 This combination reduces illness duration from 34 hours to approximately 11 hours and decreases the number of unformed stools in the first 24 hours from 3.4 to 1.2. 5

Critical caveat: Do not use loperamide if you have fever, bloody stools, or severe abdominal pain—use azithromycin alone in these situations. 1, 4

When to Seek Medical Care

Return to medical care immediately if:

• Symptoms do not improve within 24-48 hours despite self-treatment 1, 6
• Bloody diarrhea develops or worsens 1, 6
• High fever with shaking chills occurs 1
• Severe dehydration develops (decreased urination, dizziness, extreme thirst) 1
• Severe abdominal pain or distension develops 6

Why Prophylaxis Is Harmful

Routine antibiotic prophylaxis should only be considered for travelers with severe immunosuppression (HIV with low CD4 counts), inflammatory bowel disease, or those who absolutely cannot tolerate any illness due to critical trip activities. 1 Even in these rare cases, rifaximin (not azithromycin or ciprofloxacin) would be the recommended prophylactic agent. 1

The harms of prophylaxis include:

• Acquisition of multidrug-resistant bacteria that you carry home 1, 7
• Risk of Clostridioides difficile infection 1
• Disruption of protective gut microbiome 1
• Adverse drug effects without clear benefit 7
• Promotion of global antimicrobial resistance 2, 7

Practical Summary

Ask your physician for a prescription for azithromycin 500 mg tablets (take six tablets total for either a single 1000 mg dose or 500 mg daily for 3 days), not ciprofloxacin. 1, 2 Purchase loperamide and oral rehydration salts over-the-counter before departure. 1 Use these medications only if moderate-to-severe diarrhea develops during travel, not as prevention. 1