Amoxicillin/clavulanic acid is a combination penicillin-type antibiotic used to treat a wide variety of bacterial infections. It works by stopping the growth of bacteria. This antibiotic treats only bacterial infections. It will not work for viral infections (such as common cold, flu). Unnecessary use or misuse of any antibiotic can lead to its decreased effectiveness.Amoxicillin and clavulanate potassium is a combination medicine used to treat many different infections caused by bacteria, such as sinusitis, pneumonia, ear infections, bronchitis, urinary tract infections, and infections of the skin.