Clavulanic acid potentiates amoxicillin activity against β-lactamase-producing organisms. The mechanism of clavulanic acid is:
- A Irreversible (suicide) inhibition of β-lactamase ✓
- B Competitive inhibition of transpeptidase (PBP)
- C Chelation of zinc in metallo-β-lactamase
- D Blockade of outer membrane porins to reduce drug efflux
Correct answer: A. Irreversible (suicide) inhibition of β-lactamase
Explanation
Clavulanic acid is a β-lactam 'suicide inhibitor': it binds irreversibly to the active site serine of class A β-lactamases, permanently inactivating the enzyme before it can hydrolyse amoxicillin. It has negligible intrinsic antibacterial activity. Metallo-β-lactamases (class B) require zinc chelators such as EDTA for inhibition; clavulanic acid does not inhibit them. Tazobactam and sulbactam share the same suicide inhibitor mechanism.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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