A patient with a severe infection due to vancomycin-resistant Enterococcus (VRE) is treated with daptomycin. What is the mechanism of action of daptomycin?

• A Inhibits cell wall synthesis by binding lipid II
• B Inhibits DNA gyrase
• C Inhibits protein synthesis at 50S subunit
• D Depolarizes bacterial cell membrane ✓

Explanation

Daptomycin is a lipopeptide that inserts into the bacterial cell membrane in a calcium-dependent manner, causing rapid depolarization, potassium efflux, and cell death. It does not inhibit cell wall synthesis or protein synthesis. It is inactivated by pulmonary surfactant, so it is not used for pneumonia.

Reference: Katzung: Basic & Clinical Pharmacology, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.