Amoxicillin / clavulanate (oral)
Orals / systemic · Rx
Trade namesAugmentin
Drug classPenicillin + beta-lactamase inhibitor, systemic
Strength250/125 mg, 500/125 mg, 875/125 mg tablets; oral suspension
AvailabilityRx
Mechanism of actionAmoxicillin inhibits bacterial cell-wall synthesis; clavulanate is a beta-lactamase inhibitor that extends coverage to beta-lactamase-producing Staph aureus, H. influenzae and other otherwise-resistant organisms.
Indication / reason for useFirst-line oral cover for preseptal cellulitis and an infected internal hordeolum / chalazion (Staph aureus, Strep, H. influenzae); dacryocystitis; adjunct for lid-margin infections.
Usual adult dosingAdults: 875/125 mg PO twice daily (or 500/125 mg three times daily) for 7-10 days. Reassess at 48 h; refer urgently if post-septal (orbital) signs develop.
PreservativeN/A (oral) , a preservative-free option exists
Contact lensesNo direct lens interaction.
Common / important adverse effectsGI upset and diarrhea (more than amoxicillin alone), rash, candidiasis; rare cholestatic hepatitis, more common in older adults and with longer courses.
Contraindications & cautionsPenicillin / beta-lactam allergy; prior amoxicillin-clavulanate-associated cholestatic jaundice or hepatic dysfunction; avoid in infectious mononucleosis (rash risk).
Pregnancy / lactationConsidered safe in pregnancy and lactation; first-line where a systemic antibiotic is needed and there is no penicillin allergy.
Practice notesPreferred first-line over doxycycline for preseptal cellulitis given its pregnancy and pediatric safety; reserve doxycycline for penicillin allergy, MRSA risk, or lid/surface disease that benefits from its anti-inflammatory effect.
Chair-side reference only. Dosing, contraindications and pregnancy guidance here are not exhaustive. Confirm against the current prescribing information and the patient’s full history before prescribing or advising.