GENERATION OF PHARMACOKINETIC DATA DURING ROUTINE THERAPEUTIC DRUG-MONITORING - BAYESIAN-APPROACH VS PHARMACOKINETIC STUDIES

In three groups (each n = 12) of unselected hospitalized patients trea ted either with digoxin, theophylline, or gentamicin routinely perform ed TDM measurement of trough steady-state plasma levels (+ peak levels in case of gentamicin) was combined with a pharmacokinetic study at s teady state (multiple blood sampling during one dosing interval). Phar macokinetic parameters (apparent volume of distribution V(d), total pl asma clearance CL) needed for individualization of dosage were evaluat ed by the Bayesian approach and a model-(in)dependent pharmacokinetic program (TOPFIT). Comparison of both methods revealed some small diffe rences in the pharmacokinetic parameters for all three drugs. Mean dev iations of the Bayesian estimates from the pharmacokinetic calculation s of the three drugs ranged between 20 and 38% for V(d) and between 13 and 22% for CL, indicating that the Bayesian approach provided reliab le pharmacokinetic estimates for individualizing drug dosage under rou tine conditions. Therefore, it is suggested that routine TDM combined with Bayesian-based analyses can be regarded as an alternative to phar macokinetic studies in clinically relevant populations.