Vancomycin is often started empirically for gram-positive and MRSA coverage. Although effective and generally well-tolerated, emerging resistance and side-effect profiles limit its use in some patients. Two alternatives are Linezolid and Daptomycin.
Linezolid
600 mg IV every 12 hours
No renal dosing
Better lung penetration in pneumonia (compared to Vancomycin)
Side effects: Serotonin Syndrome (w/ concurrent MAOIs), hypersensitivity reaction, and myelosuppresssion
Daptomycin
4 mg/kg IV once daily (skin/subcutaneous tissues infection), 6 mg/kg IV once daily (bacteremia or endocarditis), or 6-8mg/kg IV once daily (bacteremia with intravascular line)
Renally dosed by altering administration frequency; no change in dose.
NEVER use for pneumonia; pulmonary surfactant binds and inactivates drug.
Side effects: Reversible rhabdomyolysis (requires weekly CPK levels)
References
Alder, J. The Use of Daptomycin for Staphylococcus Aureus Infection in the Critical Care Medicine. Crit Care Clin 24(2008); 349-363.
