Antibiotic pills. Bottle and pills of Augmentin antibiotics. These pills contain 250 milligrams (mg) of the penicillin drug amoxycillin trihydrate and 125mg of potassium clavulanate. Amoxycillin works by preventing the formation of bacterial cell walls. The potassium clavulanate denatures a bacterial enzyme which can break down the amoxycillin, making the preparation more effective than amoxycillin alone. This is a broad spectrum antibiotic which can be used to treat a variety of infections.