Augmentin antibiotic pills. Bottle and pills of the antibiotic drug Augmentin (also known by the name co-amoxiclav). Antibiotic drugs are used to treat bacterial infections. Augmentin is the tradename for a combination of two antibiotic drugs: amoxicillin and clavulanic acid. This combination makes the drug more effective against bacteria that are resistant to amoxicillin. The side-effects of this drug include diarrhoea and vomiting. Photographed in the UK.