Antibiotic (Penicillin + Beta-Lactamase Inhibitor) Pregnancy: B — safe (used in preterm premature rupture of membranes however avoid oral in PPROM — IV only for PPROM)

Co-Amoxiclav

Brand names: Augmentin

Adult dose

Dose: 375mg (250/125) three times daily or 625mg (500/125) three times daily

Route: Oral or IV

Frequency: Three times daily

IV: 1.2g three times daily. High-dose: 1.2g IV every 8h for severe infections. Duration typically 5–7 days oral.

Paediatric dose

Dose: 25 mg/kg

Route: Oral

Frequency: Twice daily

Max: 625 mg per dose

BNFc child 1 month–11 years (oral, dose by amoxicillin component): 0.25 mL/kg of 250/62 suspension three times daily, OR 0.15 mL/kg of 400/57 suspension twice daily. Suspension strengths: 125/31 (2–6 years) or 250/62 (6–12 years) per 5 mL. Dose based on amoxicillin component.

Paediatric weight-based calculator

Patient weight (kg)

Clinical pearls

Broader spectrum than amoxicillin alone — covers beta-lactamase producing organisms
First-line for: human/animal bites, diabetic foot infections, aspiration pneumonia
Cholestatic hepatitis risk is higher with co-amoxiclav than amoxicillin — take with food
Not first-line for uncomplicated community-acquired pneumonia (amoxicillin preferred)

Contraindications

Penicillin allergy
Previous co-amoxiclav-associated jaundice/hepatic dysfunction

Side effects

Diarrhoea (common)
Nausea
Rash
Cholestatic jaundice (especially if previous exposure)
Clostridium difficile
Vaginal candidiasis

Interactions

Warfarin — increased anticoagulant effect
Methotrexate — reduced excretion
Oral contraceptives — theoretical reduction in efficacy

Monitoring

LFTs if prolonged course or previous reaction
Renal function (IV use)

Reference: BNFc; PHE/UKHSA Antibiotic Guidelines; BNF. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways