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Antibiotic Pregnancy: Use with caution — safe for post-caesarean infections; CONTRAINDICATED in PPROM (ORACLE I — NEC risk)

Co-amoxiclav

Brand names: Augmentin

Adult dose

Dose: 625 mg (500/125 mg)
Route: Oral / IV
Frequency: Every 8 hours (oral); every 8 hours IV for severe infections
Max: 3.6 g/day (IV)
Used for post-caesarean surgical site infections, wound infections, endometritis, gynaecological sepsis. AVOID in preterm premature rupture of membranes (PPROM) — ORACLE I trial: associated with increased risk of NEC in neonates.

Paediatric dose

Dose: 25/6.25 mg/kg (amoxicillin/clavulanate) mg/kg
Route: Oral
Frequency: Every 8 hours
Max: Standard adult dose when child reaches appropriate weight
BNFc: suspension 125/31 or 250/62 per 5 mL depending on age; IV preparation available

Dose adjustments

Renal

Reduce dose and increase interval if eGFR <30 mL/min/1.73m²

Hepatic

Use with caution — hepatotoxicity risk; monitor LFTs in prolonged use

Paediatric weight-based calculator

BNFc: suspension 125/31 or 250/62 per 5 mL depending on age; IV preparation available

Clinical pearls

  • ORACLE I trial (2001): co-amoxiclav in PPROM associated with significantly increased rates of necrotising enterocolitis (NEC) in neonates — CONTRAINDICATED in PPROM
  • ORACLE I: erythromycin is the antibiotic of choice in PPROM (use alone; do not combine with co-amoxiclav)
  • Post-caesarean infection: covers Staphylococcus, Streptococcus, Gram-negatives, and anaerobes — broad empirical choice for wound infections
  • Cholestatic jaundice more common in older patients and with prolonged courses — check LFTs if jaundice develops
  • Clavulanic acid component responsible for much of the GI side effects — take with food to reduce GI upset

Contraindications

  • Penicillin allergy
  • History of co-amoxiclav-associated jaundice/hepatic dysfunction
  • PPROM (risk of NEC — ORACLE I trial)

Side effects

  • Diarrhoea (up to 10%)
  • Nausea
  • Rash
  • Hepatotoxicity (more common with prolonged use)
  • C. difficile infection
  • Anaphylaxis

Interactions

  • Warfarin — increased INR
  • Methotrexate — reduced renal excretion
  • OCP — theoretical interference (no dose adjustment required in current guidance)

Monitoring

  • LFTs (prolonged use)
  • Renal function
  • Signs of C. difficile infection

Reference: BNFc; BNF 90; BNFc; ORACLE I Trial (Lancet 2001); RCOG Green-top 44 (PPROM 2019); NICE CG190. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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