β-Lactamase inhibitors like clavulanic acid, sulbactam, and tazobactam are given with β-lactams because they:
- A Act as suicide substrates that irreversibly inactivate β-lactamase enzymes, protecting the co-administered β-lactam ✓
- B Enhance bacterial cell wall permeability to allow greater β-lactam uptake
- C Directly inhibit penicillin-binding proteins in resistant organisms
- D Increase renal tubular secretion of the β-lactam, raising blood levels
Correct answer: A. Act as suicide substrates that irreversibly inactivate β-lactamase enzymes, protecting the co-administered β-lactam
Explanation
Clavulanic acid, sulbactam, and tazobactam are mechanism-based (suicide) inhibitors: they bind covalently to the active site serine of class A (and some class D) β-lactamases, forming an irreversible acyl-enzyme complex that permanently inactivates the enzyme. This allows the co-administered β-lactam antibiotic to remain intact and effective against otherwise resistant organisms. These inhibitors do not alter permeability, directly target PBPs, or affect renal secretion.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.