First-lineAugmentin
Co-amoxiclav
Aminopenicillin + β-lactamase inhibitor
Workhorse for chorioamnionitis, endometritis, mastitis with abscess.
OralIV
First-line for
- Postpartum endometritis (with gent ± metro)
- Mastitis with abscess
- UTI in pregnancy (resistant E. coli)
- Septic abortion
Mechanism
Amoxicillin inhibits PBP-driven cell-wall synthesis; clavulanate blocks β-lactamases.
“PROM rule”
- Avoid in PPROM <34/40 — NEC ↑ in neonates (ORACLE)
- Use erythromycin instead for latency
Dosing
- Oral
- 625 mg TDS
- IV
- 1.2 g TDS
Contraindications
- AbsolutePenicillin anaphylaxis
- CautionPPROM <34/40 — NEC risk
- CautionCholestatic jaundice with prior co-amox use
Side effects
- Diarrhoea, C. difficile risk
- Cholestatic hepatitis (clavulanate)
- Rash
Fetal & maternal notes
- • Safe T1–T3 at usual doses
- • Avoid in PPROM <34/40 (ORACLE-II) — use erythromycin
Key interactions
Warfarin
Caution↑ INR — monitor
Methotrexate
Avoid↑ MTX toxicity
OCP
CautionPossible ↓ efficacy (theoretical)
Clinical pearls
- 💡 Cover anaerobes + Gram-negs — go-to postpartum sepsis empirical
- 💡 Add gentamicin for severe sepsis
Content last reviewed: REPLACE_ME (e.g. 2026-07)
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