Evaluation and first validation study on a simplified drug dosage algorithm for multiple organ failure patients

As reported previously, drug concentrations during continuous hemofiltration (HF) and extracorporeal lung assist (ELA) follow certain rules, which can be expressed by a simplified algorithm for dosage adjustment: Drug sieving (S, fu) depends on the protein free fraction with small limitations, while the extrarenal elimination rate is not a constant but correlates inversely with the clinical state, r = -0.34, p = 0.00067, n = 96. Up to now, more than 218 cases of drug dosage adjustments have been performed, following the described regimen: The expected concentration is obtained in 79-84% already from the first estimation for drugs such as aminoglycosides, vancomycin, teicoplanin, beta-lactam antibiotics, heart glycosides, and theophylline. Skilled therapeutic drug monitoring (TDM) with elaborated pharmacokinetic programs fails to improve these results significantly. Nevertheless, sporadic TDM is essential in these patients according to their rapidly changing clinical states.