Amoxicillin-clavulanate is a combination antibiotic medication that is used to treat bacterial infections. It contains two active ingredients, amoxicillin and clavulanate potassium.Amoxicillin is a type of penicillin antibiotic that works by killing bacteria. Clavulanate potassium is a beta-lactamase inhibitor that helps to prevent certain bacteria from becoming resistant to amoxicillin.