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.
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.
- IDSA Clinical Practice Guidelines for Skin and Soft Tissue Infections, 2024.
Disclaimer: All antibiotics are prescription-only. Before expedition consult the kit with an expedition or travel medicine physician.