Vancomycin prophylaxis in cardiac operations: determination of an optimal dosage regimen.

Vancomycin is thought to be an acceptable alternative prophylactic antibiotic to the cephalosporins in penicillin allergic patients undergoing cardiopulmonary bypass. We studied the pharmacokinetics of vancomycin in 10 patients undergoing cardiopulmonary bypass. Our results suggest that the commonly used 500 mg dose (7 mg/kg) of vancomycin given preoperatively may provide serum concentrations during cardiopulmonary bypass which are not bactericidal for many S. epidermidis strains. Thus we believe that a higher initial dose, at least 15 mg/kg, should be given.