Daptomycin

Daptomycin is a cyclic lipopeptide antibiotic active against Gram-positive organisms including methicillin-resistant Staphylococcus aureus, approved for complicated skin and skin structure infections and for S. aureus bloodstream infections including right-sided endocarditis.

Daptomycin inserts its lipid tail into the Gram-positive cytoplasmic membrane in a calcium-dependent manner, oligomerises, and causes rapid membrane depolarisation through potassium efflux. Cell death follows without cell lysis. Because the target is the membrane rather than a protein or the ribosome, it retains activity against organisms resistant to most other classes.

Yes. Daptomycin is approved by the U.S. FDA and has official prescribing information. Evidence level: approved labeling. Official prescribing information exists, based on clinical trials in people.

Reported half-life: Approximately 8 to 9 hours in patients with normal renal function, supporting once-daily dosing.

Intravenous infusion or injection.

Reported in the sources: Daptomycin is inactivated by pulmonary surfactant and is therefore ineffective in pneumonia. This is a mechanistic failure, not a spectrum gap, and is one of the more consequential facts about the drug; Skeletal muscle toxicity: creatine kinase elevation and, less often, rhabdomyolysis. Weekly CK monitoring is recommended, and concomitant statins are often held; Eosinophilic pneumonia has been reported, typically after two or more weeks of therapy, and requires immediate discontinuation; Peripheral neuropathy has been reported; It can cause a falsely prolonged prothrombin time and elevated INR depending on the reagent used.