Amoxycillin and clavulanic acid (Co-amoxyclav)

Amoxycillin is an extended spectrum aminopenicillin. But it is not active against penicillinase producing organism. Clavulanic acid is a penicillinase inhibitor which initially reversibly and then irreversibly inhibits penicillinase 2-5 except cephalosporinase. So this drug combination has a synergistic action.