Daptomisin

Daptomisin is not a widely recognized pharmaceutical name and is typically a misspelling of daptomycin, a cyclic lipopeptide antibiotic produced by Streptomyces roseosporus. Daptomycin acts by binding to bacterial membranes in a calcium-dependent fashion, causing rapid depolarization and inhibition of DNA, RNA, and protein synthesis, which leads to bacterial cell death. It is active primarily against Gram-positive organisms, including MRSA, methicillin-susceptible Staphylococcus aureus, and many Streptococcus species, as well as some Enterococcus species, including certain vancomycin-resistant strains. It has little activity against Gram-negative bacteria and is inactivated by pulmonary surfactant, limiting its use for pneumonia.

Daptomycin is administered by intravenous infusion, with weight-based dosing given once daily. It is approved for complicated skin and skin-structure infections and for bacteremia and right-sided infective endocarditis. Typical regimens include 4 mg/kg IV daily for skin infections and 6 mg/kg IV daily for bacteremia or endocarditis, adjusted for renal function. Common adverse effects include headache and nausea; serious concerns include myopathy and rhabdomyolysis, particularly when used with statins, so CK monitoring is recommended during therapy. Other potential adverse effects include eosinophilic pneumonia and injection-site reactions. It does not require hepatic dose adjustment.

Resistance can occur through mutations that decrease drug binding to the membrane; such strains are uncommon but documented. Due to the surfactant in lungs, daptomycin is not used to treat pneumonia. History: it was approved by the FDA in 2003 for complicated skin infections and later for bacteremia and right-sided endocarditis; marketed under the brand Cubicin.