Co-amoxiclav belongs to the class of antibiotics known as the penicillin group. It is a combination of clavulanic acid and amoxicillin. These two together fight the bacteria which are normally resistant to amoxicillin alone. It works by killing the infection-causing bacteria. It is one of the most common antibiotics to treat a number of bacterial infections like ear infections, skin infections, bronchitis, sinusitis, otitis media, etc.