Side by side

1. 1.Binds bacterial membrane lipids in a calcium-dependent manner and inserts its lipophilic tail.
2. 2.Depolarises the membrane, collapsing the proton motive force.
3. 3.Stops protein, DNA and RNA synthesis as a downstream consequence.
4. 4.Kills rapidly and is bactericidal without needing cell division.
5. 5.Lung surfactant binds and inactivates the drug, which explains its failure in pneumonia.

• Complicated skin and soft tissue infection
• MRSA bacteraemia
• Right-sided infective endocarditis
• Bone and joint infection (often off-label)
• Vancomycin-resistant enterococcal infection (often off-label)

• Cure rates comparable to standard therapy in skin infection and bacteraemia trials
• Rapid bactericidal killing in time-kill studies
• Muscle enzyme (creatinine kinase) rises in a small percentage of patients
• Eosinophilic pneumonia reported with prolonged use

• Raised creatinine kinase and muscle pain, occasionally rhabdomyolysis
• Eosinophilic pneumonia with longer courses
• Diarrhoea and nausea
• Headache
• Peripheral neuropathy
• Injection-site reactions

Research context only - a hospital antibiotic. Licensed dosing is 4 mg per kilogram once daily for skin infection and 6 mg per kilogram once daily for bacteraemia and endocarditis, with some guidelines using 8 to 10 mg per kilogram for difficult organisms; creatinine kinase is checked weekly. Trials assess clinical success at a test-of-cure visit 7 to 14 days after the end of therapy.

Research context only