Antibiotics in the expedition medical kit are not a full shelf but 4 drugs with different spectra — chosen to cover 90% of infections encountered on expeditions in the Himalayas, Andes, or Africa. It’s not about “just-in-case treatment” but a rescue tool when the nearest doctor is 3 days’ march away with no phone signal. In this article: 4 first-line antibiotics, their dosing, indications, interactions, and when NOT to use them.
At base camp most of my conversations about antibiotics were with the Sherpas, about dental infections they would carry for weeks before anyone found out. You had to ask directly whether they were taking anything, because they played their own complaints down. A medical kit works when somebody manages it; blister packs sitting in a rucksack settle nothing.
Four first-line antibiotics
- Azithromycin 500 mg — traveler’s diarrhea, respiratory tract infections, skin
- Amoxicillin-clavulanate (Augmentin) 875/125 mg — skin infections, sinuses, dental abscesses, wound infections
- Ciprofloxacin 500 mg — urinary tract infections, some diarrheas (when azithromycin fails)
- Metronidazole 500 mg — giardiasis, amoebae, anaerobes (abscesses, mixed infections)
Azithromycin — the expedition workhorse
- Traveler’s diarrhea (ETEC, Campylobacter, Shigella) — first choice, especially South Asia
- Acute bacterial sinusitis
- Superficial skin infections (cellulitis, impetigo)
- Bacterial bronchitis, mild community-acquired pneumonia
- Lyme disease (when doxycycline unavailable or contraindicated)
Dosing
- Diarrhea: 500 mg once daily × 3 days (or single 1000 mg dose if urgent)
- Respiratory: 500 mg once daily × 3–5 days
- Skin: 500 mg once daily × 3 days
- Contraindications: macrolide allergy, QT prolongation, myasthenia gravis
- Interactions: warfarin (↑INR), digoxin (↑concentration), statins (rhabdomyolysis risk with simvastatin)
Amoxicillin-clavulanate — broad umbrella
- Wound infections (after falls or bites — dog, monkey, human)
- Dental abscesses and periodontal infections
- Sinusitis resistant to azithromycin
- Community-acquired pneumonia
- Deep skin infections (cellulitis with fever, infected post-frostbite blisters)
- Post-bite prophylaxis (drug of choice globally)
Dosing
- Standard: 875/125 mg twice daily × 5–10 days
- Severe infections: 1000/125 mg three times daily
- Post-bite prophylaxis: 875/125 mg twice daily × 5–7 days
- Contraindications: penicillin allergy, history of Augmentin-related jaundice
- Side effects: diarrhea (10–20% — clavulanate), candidiasis, rash
Ciprofloxacin — urinary tract specialist
- Urinary tract infections (UTI) — first choice on expeditions
- Traveler’s diarrhea — alternative to azithromycin (Africa, Latin America)
- Bacterial prostatitis
- External otitis (if solely oral route)
Dosing
- Uncomplicated UTI: 250 mg twice daily × 3 days
- Complicated UTI or men: 500 mg twice daily × 7 days
- Diarrhea: 500 mg twice daily × 3 days
- Contraindications: pregnancy, children <18 yrs (growth cartilage), myasthenia gravis, Achilles tendinopathy history
- Photoneurotoxicity: avoid sun during treatment + 48 h after
- Interactions: warfarin, digitalis glycosides, theophylline (significant)
Note: in South Asia Campylobacter resistance to fluoroquinolones is rising — we prefer azithromycin there. Ciprofloxacin still works well in Africa and Latin America for diarrhea.
Metronidazole — for parasites and anaerobes
- Giardiasis — prolonged diarrhea (>7 days), bloating, “sulfur” belching, fatty stools
- Amoebiasis (Entamoeba histolytica) — bloody diarrhea, abdominal pain, fever
- Anaerobic bacteria — deep abscesses, bite wound infections
- Trichomoniasis, bacterial vaginosis
- Clostridioides difficile — post-antibiotic diarrhea (severe cases)
Dosing
- Giardiasis: 500 mg three times daily × 5–7 days
- Amoebiasis: 750 mg three times daily × 7–10 days
- Anaerobes + mixed infections: 500 mg three times daily × 7 days (combined with Augmentin or ciprofloxacin)
- Contraindications: first trimester of pregnancy, allergy
- Disulfiram reaction with alcohol: nausea, tachycardia, hypotension — avoid alcohol during and 48 h after
When NOT to give antibiotics
- Common cold — viral, antibiotic won’t help and disrupts flora
- Mild diarrhea without fever/blood — hydration suffices
- Dry cough without fever/dyspnea — usually viral bronchitis
- Fever without localization — observe 24–48 h first, then possibly antibiotic
- Minor abrasions and superficial wounds — hygiene + dressing suffices in healthy person
Principle: if uncertain whether bacterial, and you have access to care within 24 h — observe rather than give antibiotic. Antibiotic overuse on expedition means no efficacy when really needed.
Recommended kit for a 2–3 week expedition
- Azithromycin 500 mg — 6 tablets (2 diarrhea courses OR 1 respiratory course)
- Augmentin 875/125 mg — 20 tablets (1 full 10-day course)
- Ciprofloxacin 500 mg — 14 tablets (reserve UTI + diarrhea)
- Metronidazole 500 mg — 21 tablets (7-day giardia/amoeba course)
All are prescription-only. An expedition medicine physician writes these without issue, justifying high-altitude trip. Don’t buy in destination country — counterfeit risk (especially Nepal, India, African nations) is real.
Frequently asked questions
Why not doxycycline?
Doxycycline is an excellent drug but has key expedition limitations: photosensitivity (critical at high-altitude UV), contraindicated in pregnancy and children, interactions with calcium/magnesium/iron supplements. In the 4-drug kit above I don’t include it, but if planning malaria-endemic region with doxycycline as prophylaxis, it’s an additional drug.
What if I’m allergic to penicillins?
Skip Augmentin and substitute azithromycin (increased tablet count) + clindamycin (skin and dental infections) or third-generation cephalosporin (cefuroxime 500 mg twice daily) if allergy is not immediate (anaphylaxis). Note: ~5% of penicillin-allergic individuals also react to cephalosporins. For anaphylaxis history — choose azithromycin + clindamycin.
Can I give my antibiotic to a sick teammate?
Only if you are an expedition physician on the team with clinical decision-making authority. As non-medical personnel, you don’t have qualifications and don’t know the teammate’s history (allergies, pregnancy, chronic diseases, other medications). Universal rule: expedition antibiotics are for YOU. If teammate falls ill, contact expedition doctor via radio/phone/satellite, OR initiate evacuation.
How to store antibiotics on expedition?
Most antibiotics are stable -20°C to 40°C for brief periods. 2–3 week courses survive typical expedition conditions. Special notes: azithromycin and ciprofloxacin — prefer room temperatures, avoid freezing. Metronidazole — stable. Augmentin — most moisture- and heat-sensitive, keep in dry packaging inside backpack (not pocket against body). Always check expiration — don’t use expired drugs, especially tetracyclines (nephrotoxic past expiration).
How long is the antibiotic course — shorten if improved?
Depends on drug. Azithromycin — complete 3 days regardless of improvement (long half-life — acts days after last dose). Augmentin — minimum 5 days for skin/respiratory, 7–10 days for wound. Ciprofloxacin in UTI — minimum 3 days. Metronidazole in giardiasis — full 5–7 days or recurrence. Generally: DO NOT SHORTEN antibiotic courses, risking resistance selection and recurrence. Exception: if no improvement after 48 h — change drug or consult.
References
- Riddle MS, Connor BA, Beeching NJ, et al. Guidelines for the prevention and treatment of travelers’ diarrhea. J Travel Med. 2017;24(suppl_1):S57–S74.
- CDC Yellow Book 2024 — Travelers’ Diarrhea & Infectious Diseases chapters.
- Stevens DL, et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America. Clin Infect Dis. 2014;59(2):e10–e52.
Disclaimer: All antibiotics are prescription-only. Before expedition consult the kit with an expedition or travel medicine physician.