A 35-year-old woman with recurrent UTI is prescribed amoxicillin-clavulanate. Clavulanate is added primarily because it:

• A Enhances renal tubular secretion of amoxicillin
• B Increases amoxicillin absorption from the gastrointestinal tract
• C Irreversibly inhibits beta-lactamase enzymes produced by resistant bacteria ✓
• D Extends the post-antibiotic effect of amoxicillin

Explanation

Clavulanate is a beta-lactamase inhibitor that irreversibly ('suicide inhibitor') binds and inactivates beta-lactamase enzymes, thereby protecting amoxicillin from degradation by resistant organisms such as MRSA-like beta-lactamase producers. It has minimal intrinsic antibacterial activity on its own. This combination restores the spectrum of amoxicillin against beta-lactamase-producing strains of H. influenzae, E. coli, and Staphylococcus aureus.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.