Daptomysiini

Daptomysiini, known in English as daptomycin, is a cyclic lipopeptide antibiotic produced by Streptomyces roseosporus. It is used to treat certain Gram-positive infections and is administered exclusively by intravenous infusion.

The antibiotic exerts its bactericidal effect through a calcium-dependent interaction with bacterial cell membranes. Daptomysiini inserts into the membrane, causing rapid depolarization and inhibition of essential processes such as DNA, RNA, and protein synthesis, which leads to cell death without lysis.

Its activity is primarily against Gram-positive bacteria. It is active against many strains of methicillin-resistant Staphylococcus aureus (MRSA) and other resistant Gram-positive pathogens, including some enterococci. It has limited activity against Gram-negative organisms due to the outer membrane barrier and is not effective for pneumonia, in part because lung surfactant can inactivate the drug.

Common approved indications include complicated skin and skin structure infections (cSSSI) and bacteremia, including right-sided infective endocarditis due to S. aureus. Dosing is weight-based and IV; typical regimens range from about 4–6 mg/kg once daily for cSSSI to 6–8 mg/kg once daily for bacteremia or right-sided endocarditis, with adjustments for renal function. The drug is primarily renally excreted, and monitoring is recommended in patients with renal impairment.

Adverse effects include myopathy and an elevated risk of rhabdomyolysis, particularly when used with statins; creatine phosphokinase monitoring is advised. Eosinophilic pneumonia is a rare but serious adverse event. Resistance can develop through changes that reduce drug binding to the membrane, such as membrane charge alterations, and remains relatively uncommon but has been observed.

Daptomysiini was discovered in the late 20th century and approved for medical use in the early 2000s. It is considered a valuable option for certain difficult Gram-positive infections, with specific limitations regarding lung infections and Gram-negative coverage.