Beta-lactam / Beta-lactamase Inhibitor Combination Pregnancy: Use should be avoided during pregnancy unless considered essential by the physician; in a single study in women with preterm premature rupture of the foetal membranes, prophylactic amoxicillin/clavulanic acid was reported as possibly associated with an increased risk of necrotising enterocolitis in neonates. Both substances are excreted into breast milk — use during breast-feeding only after benefit/risk assessment by the physician in charge.

Co-amoxiclav (Open Fracture Antibiotic Prophylaxis)

Brand names: Augmentin

Co-amoxiclav (amoxicillin with clavulanic acid) is used in trauma as intravenous antibiotic prophylaxis for open (compound) fractures, given as soon as possible after injury to reduce infection of the contaminated wound. This page focuses on that open-fracture prophylaxis indication.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Surgical prophylaxis (adults and children 40 kg and over): 1000 mg/200 mg to 2000 mg/200 mg amoxicillin/clavulanic acid given at induction of anaesthesia

Route: Intravenous — slow intravenous injection over 3 to 4 minutes directly into a vein or via a drip tube, or by infusion over 30 to 40 minutes. Not suitable for intramuscular administration.

Frequency: Single dose at induction of anaesthesia for procedures less than 1 hour; for procedures greater than 1 hour, the same dose at induction plus up to 3 doses of 1000 mg/200 mg in 24 hours

Max: This presentation delivers a total daily dose of 3000 mg amoxicillin and 600 mg clavulanic acid when given as 1000 mg/200 mg every 8 hours. Doses of 2000 mg/200 mg can only be achieved by using an alternative intravenous formulation of co-amoxiclav.

Doses are expressed throughout in terms of amoxicillin/clavulanic acid content. The SPC gives this regimen for surgical prophylaxis generally — OPEN FRACTURE prophylaxis is not separately specified and no fracture-specific timing or duration is stated; confirm against local trauma/orthopaedic guidance. §4.2 also states that clear clinical signs of infection at operation will require a normal course of intravenous or oral therapy post-operatively. TREATMENT (not prophylaxis) dose for adults and children 40 kg and over is 1000 mg/200 mg every 8 hours; some infections (e.g. osteomyelitis) require longer periods of treatment, and treatment should not be extended beyond 14 days without review. If a higher daily dose of amoxicillin is required, an alternative intravenous formulation should be selected to avoid unnecessarily high daily doses of clavulanic acid. Elderly: no dose adjustment considered necessary. Hepatic impairment: dose with caution and monitor hepatic function at regular intervals. PAEDIATRIC (§4.2, children under 40 kg — treatment dose only; no paediatric surgical-prophylaxis dose is stated): children aged 3 months and over 25 mg/5 mg per kg every 8 hours; children aged less than 3 months or weighing less than 4 kg 25 mg/5 mg per kg every 12 hours, given by infusion only under 3 months. Because the paediatric dose is a two-component figure and is a treatment (not prophylaxis) dose, it has not been rendered as a structured per-kg value — verify against a children's formulary. PROVENANCE: fetched eMC product is Co-Amoxiclav 1000 mg/200 mg powder for solution for injection/infusion (both components of the fixed combination are described). §4.5 (interactions) was not part of the fetched bundle; §4.4 was truncated at the source-fetch limit.

Dose adjustments

Renal

No dose adjustment if creatinine clearance is greater than 30 ml/min. Adults and children 40 kg and over — CrCl 10–30 ml/min: initial dose 1000 mg/200 mg then 500 mg/100 mg twice daily; CrCl less than 10 ml/min: initial dose 1000 mg/200 mg then 500 mg/100 mg every 24 hours; haemodialysis: initial dose 1000 mg/200 mg then 500 mg/100 mg every 24 hours plus a dose of 500 mg/100 mg at the end of dialysis. Children under 40 kg — CrCl 10–30 ml/min: 25 mg/5 mg per kg every 12 hours; CrCl less than 10 ml/min: 25 mg/5 mg per kg every 24 hours; haemodialysis: 25 mg/5 mg per kg every 24 hours plus 12.5 mg/2.5 mg per kg at the end of dialysis.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substances, to any of the penicillins or to any of the excipients
History of a severe immediate hypersensitivity reaction (e.g. anaphylaxis) to another beta-lactam agent (e.g. a cephalosporin, carbapenem or monobactam)
History of jaundice/hepatic impairment due to amoxicillin/clavulanic acid

Side effects

Diarrhoea (common); nausea, vomiting and indigestion (uncommon)
Mucocutaneous candidosis (common) and overgrowth of non-susceptible organisms
Skin rash, pruritus and urticaria (uncommon); erythema multiforme (rare); Stevens-Johnson syndrome, toxic epidermal necrolysis, AGEP and DRESS (frequency not known)
Rises in AST and/or ALT (uncommon); hepatitis and cholestatic jaundice (frequency not known)
Anaphylaxis, angioneurotic oedema, Kounis syndrome and hypersensitivity vasculitis (frequency not known)
Antibiotic-associated colitis, drug-induced enterocolitis syndrome (reported mainly in children), convulsions in renal impairment or with high doses, and reversible leucopenia/thrombocytopenia (rare)

Interactions

Allopurinol — concomitant use during treatment with amoxicillin can increase the likelihood of allergic skin reactions (§4.4)
Full §4.5 interaction section was not retrieved in this bundle — check the SPC directly before relying on this list

Clinical monograph

How it works

Amoxicillin inhibits bacterial cell-wall synthesis via penicillin-binding proteins, while clavulanic acid irreversibly inhibits many bacterial beta-lactamases, restoring activity against beta-lactamase-producing staphylococci and Gram-negative organisms relevant to wound contamination.

Prescribing in practice

Do not use in patients with previous penicillin anaphylaxis or with a history of co-amoxiclav-associated jaundice or hepatic dysfunction; verify allergy status urgently in the trauma setting and use an alternative regimen if needed.
Give early after open-fracture injury and alongside thorough wound management and tetanus prophylaxis, as antibiotics complement but do not replace timely surgical debridement.
Co-amoxiclav can cause cholestatic jaundice (more often in older men and with longer courses) and the dose frequency needs adjustment in renal impairment — follow local open-fracture and the SPC guidance.

Monitoring

Monitor the wound and systemic response, observe for hypersensitivity, and check liver function if therapy is prolonged or jaundice is suspected.

Counselling the patient

Tell staff about any penicillin allergy or previous reaction to this antibiotic before it is given.
Report yellowing of the skin or eyes, dark urine, rash or breathing difficulty.
Understand that the antibiotic works alongside, and does not replace, surgical cleaning of the wound and tetanus cover.

Evidence & guidelines

NICE and BOAST open-fracture standards recommend prompt intravenous antibiotics after injury together with timely debridement and stabilisation to reduce deep infection.

Reference: BOAST Open Fracture Guidelines 2017; NICE NG125 (SSI); SPC Augmentin IV; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways