Effects of cardiopulmonary bypass on teicoplanin serum disposition

The time course of teicoplanin (T) serum concentrations was determined in 6 patients who had undergone cardiopulmonary bypass (CPB). The drug was given i.v. (12 mg/kg) 85-140 min before starting CPB. Serum concentrations of T were measured with an automated fluorescence polarization immunoassay, at appropriate times before, during and after CPB (total sampling interval: 12 h). Five min after initiating CPB, T serum concentrations decreased, on average, by 29% and remained less than the expected values (values extrapolated from the decay curve, measured excluding the CPB period) over the subsequent 60 min. When CPB was discontinued, the T serum concentrations rebounded to the expected values within 5 min. The mean area under the curve (AUC) during CPB was significantly lower than the mean extrapolated AUC. It was concluded that CPB reversibly reduced T serum concentrations, probably due to drug redistribution. Nevertheless, T serum levels were always above the mean inhibitory concentration (MIC) of the most common pathogenic organisms associated with CPB surgery infections.