Cefadroxil
Cefadroxil
Brand names:Duricef, Ultracef
A first-generation oral cephalosporin antibiotic. The TCCC 2026 Guidelines designate cefadroxil 1 gram PO once daily as the preferred oral antibiotic for combat wound prophylaxis, replacing moxifloxacin in prior TCCC versions. Also indicated as the oral alternative for penetrating eye trauma prophylaxis.
Pharmacology and Actions
Cefadroxil inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs) and blocking peptidoglycan cross-linking. This bactericidal mechanism is shared across the beta-lactam antibiotic class (penicillins and cephalosporins).
First-generation cephalosporins have predictable activity against gram-positive skin flora (Staphylococcus aureus including methicillin-sensitive strains, Streptococcus pyogenes, Streptococcus agalactiae) and limited gram-negative coverage. They are preferred for skin and soft tissue infection treatment when MRSA is unlikely.
The drug has excellent oral bioavailability (approximately 90%), good tissue penetration, and a half-life supporting twice-daily dosing. Coverage does not include MRSA, anaerobes, or many gram-negative pathogens beyond E. coli, Klebsiella, and Proteus mirabilis.
Cefadroxil is excreted primarily unchanged in urine. Renal dosing adjustment is required for significant renal impairment.
Indications
- Combat wound prophylaxis when oral antibiotics are appropriate (TCCC 2026, preferred PO option)
- Penetrating eye trauma prophylaxis when IV/IM not available (TCCC 2026)
- Confirmed skin and soft tissue infections from gram-positive flora
- Pharyngitis (Streptococcus pyogenes)
- Urinary tract infections from susceptible organisms
- Cellulitis without abscess
Absolute Contraindications
- Known cefadroxil or cephalosporin allergy
- Severe penicillin allergy with anaphylaxis history (relative; cross-reactivity approximately 1-3% but variable)
Precautions and Side Effects
Most common side effects are gastrointestinal (nausea, diarrhea, abdominal pain). C. difficile-associated colitis can occur, particularly with prolonged use.
Allergic reactions ranging from mild rash to anaphylaxis are possible. Cross-reactivity with penicillins is real but lower than historically taught (approximately 1-3% rather than 10%). Patients with mild penicillin allergy (rash without anaphylaxis) can generally tolerate cephalosporins. Patients with documented penicillin anaphylaxis should generally avoid cephalosporins unless allergy testing confirms tolerability.
Renal impairment requires dosing adjustment. Standard dosing assumes normal renal function.
Drug interactions are minimal. The most clinically relevant interaction is with probenecid, which decreases renal clearance and increases cefadroxil levels.
Adult Dosing
TCCC 2026 penetrating eye trauma (Section 9): 1 gram PO as soon as possible (alternative to ceftriaxone 2 g IV/IM when IV/IM not available)
Standard skin/soft tissue infection: 500 mg PO twice daily for 7 to 10 days
Pharyngitis: 1 gram PO once daily for 10 days
Onset: 1 to 2 hours (absorption); clinically meaningful antibacterial concentrations within 2 to 4 hours
Pediatric Dosing
Pediatric skin/soft tissue: 30 mg/kg/day PO divided twice daily, maximum 2 grams/day
Pediatric pharyngitis: 30 mg/kg/day PO once daily, maximum 1 gram/day
Pharmacokinetics
Peak Effect: 1 to 2 hours
Duration: 12 hours (twice-daily dosing)
Storage and Handling
Store at room temperature (15 to 30 degrees Celsius). Protect from light and moisture.
Cefadroxil is supplied as:
Capsules: 500 mg
Tablets: 1 gram
Oral suspension: 250 mg/5 mL or 500 mg/5 mL (requires reconstitution)
The capsule and tablet forms are stable across standard tactical operating temperature ranges. Oral suspension is less practical for tactical pack stocking due to refrigeration requirements after reconstitution.
The drug is stable for the duration of its labeled expiration when stored within specified temperature range.
Reconstitution:
Capsule and tablet forms require no reconstitution.
Oral suspension: Add water to the dry powder per manufacturer instructions, shake well to mix, refrigerate after reconstitution. Use within 14 days. Discard unused portion.
TCCC and TECC Role
The May 2026 TCCC Guidelines designate cefadroxil as the preferred oral antibiotic for combat wound prophylaxis when the casualty can take PO medications. Section 12b establishes the doctrine:
1, PO preferred (able to take oral): Cefadroxil 1 gram PO once daily
2. PO alternative: Cephalexin 500 mg PO every 6 hours
3. IV/IO/IM (unable to take PO due to shock or unconsciousness): Ceftriaxone 2 grams IV/IO/IM once daily
This is a doctrine change from prior TCCC versions that listed moxifloxacin as the preferred oral antibiotic. The 2026 update reflects shifts in evidence regarding antibiotic selection, fluoroquinolone safety profiles, and pathogen coverage for combat wound infections.
Cefadroxil also appears in Section 9 (Penetrating Eye Trauma) as the oral alternative when ceftriaxone IV/IM is not feasible. Section 9 specifies: "Administer ceftriaxone 2g IV or IM, or cefadroxil 1g orally as soon as possible."
The drug's role in TCCC 2026 is therefore central, not peripheral. Trained providers should consider cefadroxil the default oral antibiotic for combat wounds and penetrating eye injuries.
The shift to cefadroxil in TCCC 2026 simplifies tactical antibiotic logistics. A single drug now covers most combat wound prophylaxis scenarios when PO administration is feasible: skin and soft tissue wounds, penetrating eye trauma, and prolonged field care continuation therapy. Stocking cefadroxil eliminates the need to carry moxifloxacin for tactical wound prophylaxis under current doctrine.
Operationally, the once-daily dosing matches the practical realities of prolonged casualty care. A casualty who receives cefadroxil at injury or at the casualty collection point will have therapeutic antibacterial concentrations onboard for 24 hours, supporting evacuation across most operational distances.
For trained providers, the practical takeaway is to update mental models from prior TCCC training. Moxifloxacin is no longer the TCCC PO antibiotic. Cefadroxil 1 gram PO daily is preferred; cephalexin 500 mg PO every 6 hours is the alternative. For casualties who cannot take PO, ceftriaxone 2 grams IV/IO/IM daily is the IV/IM choice.
A practical note on procurement: cefadroxil is widely available and inexpensive. Capsule and tablet forms have long shelf lives and tolerate operational storage temperatures. Unit medical formularies should now stock cefadroxil for combat wound prophylaxis.
Reaching for moxifloxacin as the oral antibiotic for combat wound prophylaxis. This was correct in earlier TCCC versions but is no longer the preferred regimen. The May 2026 update specifies cefadroxil 1 gram PO daily as the preferred oral option, with cephalexin 500 mg PO every 6 hours as the alternative. A second common error is delaying cefadroxil administration in penetrating eye trauma when ceftriaxone IV/IM is not immediately available. Section 9 of the 2026 guidelines is clear: cefadroxil 1 gram PO is acceptable as soon as possible if the IV/IM route cannot be used. Don't withhold antibiotic prophylaxis waiting for IV access.
This drug profile is provided as educational reference material for trained medical providers. It is not medical advice, not a substitute for formal training, and not a substitute for current published guidelines or medical direction.
Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances are subject to additional handling, accountability, and documentation requirements per DEA and state law. Always verify dosing, indications, contraindications, and route of administration against current published guidelines and your local protocols before administration.
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Penn Tactical Solutions publishes this reference for educational purposes. PTS does not provide medical direction and does not assume responsibility for clinical decisions made in the field. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Educational reference for trained medical providers. Not medical advice. Not a substitute for formal training, current published guidelines, or medical direction. Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances require additional storage, accountability, and documentation per DEA and state law.
In a medical emergency, call 911. This reference is not a substitute for emergency medical services.
Verify dosing, indications, and contraindications against current published guidelines and your local protocols before administration. Confirm content currency against the source citation. Penn Tactical Solutions does not provide medical direction. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Cefadroxil
| PO | TCCC 2026 combat wound prophylaxis (Section 12b): 1 gram PO once daily TCCC 2026 penetrating eye trauma (Section 9): 1 gram PO as soon as possible (alternative to ceftriaxone 2 g IV/IM when IV/IM not available) Standard skin/soft tissue infection: 500 mg PO twice daily for 7 to 10 days Pharyngitis: 1 gram PO once daily for 10 days (1 to 2 hours (absorption); clinically meaningful antibacterial concentrations within 2 to 4 hours) |