TDM coupled with Bayesian forecasting should be considered an invaluable tool for optimizing vancomycin daily exposure in unstable critically ill patients

A randomized two-arm prospective study was planned to assess the role of therapeutic drug monitoring (TDM) coupled with a Bayesian approach in tailoring vancomycin dosages in unstable critically ill patients. Group A (n = 16) had their regimen adjusted day-by-day according to TDM and Bayesian forecasting (D-a); group B (n = 16) had their regimen adjusted day-by-day according to Moellering's nomogram (D-M). Blood samples were collected every 1-2 days to assess the trough and peak plasma concentrations. In group A, the tailored D-a required for optimizing vancomycin exposure were considerably higher than the D-M in 7/16 cases, and lower than the D-M in 1/16 cases. In group B, standard D-M caused under-treatment in 3/16 cases and over-treatment in 4/16 cases. Most of these patients concomitantly had some conditions that might have altered vancomycin disposition. The TDM-guided Bayesian-based approach should be considered an invaluable tool for clinicians to handle appropriately on real-time vancomycin therapy in critically ill patients. (C) 2002 Elsevier Science B.V. and International Society of Chemotherapy. All rights reserved.