Antimicrobial
Lipopeptides (daptomycin)
Calcium-dependent membrane depolarizer
LY-poh-pep-tides
High-yield clue
Daptomycin causes calcium-dependent membrane depolarization but is inactivated by pulmonary surfactant, so it is not used for pneumonia.
Overview
A cyclic lipopeptide class represented by daptomycin, studied for inserting into the Gram-positive cytoplasmic membrane in a calcium-dependent way and causing depolarization.
Classification
- Cell-membrane-active agent
- Calcium-dependent insertion
- Rapidly bactericidal
- Gram-positive spectrum only
Lab & identification clues
- Membrane depolarization / potassium efflux concept
- Surfactant inactivation (not for lung infection) vocabulary
- Creatine kinase / myopathy monitoring concept
Associations
- MRSA and VRE coverage vocabulary
- Bloodstream and skin study associations
- Requires calcium and phosphatidylglycerol for activity
Commonly confused with
- Polymyxins (colistin)
- Vancomycin
Your notes
Original mechanism summary for microbiology study. Sources checked: CDC antimicrobial-resistance guidance, NCBI Bookshelf Medical Microbiology, and standard coursework frameworks; reviewed 2026-06. Covers class, mechanism, and resistance vocabulary only; no prescribing, dosing, or patient-specific treatment guidance.