Pharmacology · Class
Lipopeptides !
Antibiotics that insert into the gram-positive membrane and depolarize it; daptomycin is the only one in use.
Updated 2026-11-01
What they are
Cyclic lipopeptides kill gram-positive bacteria, including MRSA and many vancomycin-resistant strains, by attacking the cell membrane. Daptomycin, from Streptomyces roseosporus, is the only member in clinical use.
Mechanism of action
The lipid tail anchors the drug in the bacterial inner membrane, which depolarizes; the loss of membrane potential stops DNA, RNA and protein synthesis and the cell dies. Killing is concentration-dependent. Gram-negative bacteria are not affected.
Target: Cytoplasmic membrane of gram-positive bacteria
Drugs in this class
Test yourself
Think of the answer, then tap the question to see it.
Why is daptomycin not used for pneumonia?
Pulmonary surfactant binds and inactivates it, even though it reaches the lung.
Which laboratory test is followed weekly during daptomycin treatment?
Creatine phosphokinase (CPK), because daptomycin can cause myopathy and rhabdomyolysis.
How does daptomycin kill bacteria?
It inserts into the gram-positive membrane and depolarizes it; without membrane potential, DNA, RNA and protein synthesis stop.
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 58 (McGraw Hill, 2023); DailyMed - DAPTOMYCIN injection, powder, lyophilized, for solution (DailyMed (U.S. National Library of Medicine), 2026).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.