Amoxicillin/clavulanate

Penicillin + Beta-Lactamase Inhibitor·Infectious Diseases - Penicillins

Bite wounds, severe exacerbations of COPD, diabetic foot infections

Authority requiredPBSBETA-LACTAMAugmentin, CuramS4+1

Max Dose

875/125 mg BD

Half-life

1 h

Hepatotoxicity

HIGH RISK

Diarrhea

COMMON

Rapid Summary

Overview

Amoxicillin paired with clavulanic acid to overcome beta-lactamase producing bacteria. The go-to for animal/human bites and mixed intra-abdominal infections.

Maximum Dose

Max 875/125 mg BD (Oral).

Clinical Focus

The clavulanate component is notoriously hepatotoxic. Avoid courses longer than 10-14 days.

Bottom Line

Amoxicillin/clavulanate is the standard beta-lactamase-stable penicillin for resistant RTIs, UTIs, and bite wounds, but the clavulanate component frequently causes diarrhoea and hepatotoxicity risk increases with prolonged use.

Formulation & Access

Brand Names

Augmentin, Curam

Oral Routes

Tablets (500/125 mg, 875/125 mg).

Parenteral

Ampoule (1 g/200 mg) for IV use.

Prescribing & PBS

Authority Required (PBS) for specific indications.

Indications & Use

Primary

PBSTGA

Bite wounds, severe exacerbations of COPD, diabetic foot infections.

Clinical Place

Essential step-up when beta-lactamase resistance is suspected (e.g., H. influenzae, M. catarrhalis, S. aureus).

Quick reference

Class & Role

Penicillin + Beta-Lactamase Inhibitor — Amoxicillin paired with clavulanic acid to overcome beta-lactamase producing bacteria.

Route / Formulation

Tablets (500/125 mg, 875/125 mg). (Augmentin, Curam)

Usual Dose & Max

PO 500/125 mg BD or TDS. Max 875/125 mg BD (Oral).

Key Indication Doses

Animal / Human Bites: PO 500/125 mg BD or TDS. Severe Respiratory / Intra-abdominal: PO 875/125 mg BD. OR IV 1.2 g q8h. Renal Impairment: Avoid the 875/125 mg tablet if eGFR < 30. Use 500/125 mg instead.

Best Uses

Avoid / Cautions

History of Augmentin-associated jaundice/hepatic dysfunction or severe penicillin allergy. Pregnancy Category B1 (Generally safe, but avoid close to term due to theoretical necrotising enterocolitis risk in neonate).

Key Risks

Hepatic: Cholestatic jaundice and hepatitis. Risk increases sharply with age and courses > 14 days. Gastrointestinal: Severe diarrhea, nausea, C. difficile infection. Immunological: Anaphylaxis (cross-reactive with all penicillins).

Key Interactions

Increases toxicity of Methotrexate (reduced renal clearance). Can prolong INR in patients on Warfarin.

Monitoring

Monitor LFTs if therapy extends beyond 7-10 days. Warn patients to report dark urine, pale stools, or yellow sclera even *after* stopping the drug.

Clinical Pearl

If you need more amoxicillin, add plain amoxicillin. Never prescribe Augmentin 'TDS' if using the 875/125mg tablets—doubling the dose doubles the clavulanate, triggering massive diarrhea and severe hepatotoxicity.

Access

Authority requiredAugmentin, Curam

Brand: Augmentin, Curam
PBS status: Authority required
Formulation: Tablets (500/125 mg, 875/125 mg)