Therapeutic Drug Monitoring of Quetiapine: Effect of Coadministration with Antiepileptic Drugs in Patients with Psychiatric Disorders

摘要: Antiepileptic agents, particularly those with mood-stabilizing properties, are increasingly used in the manage- ment of psychiatric disorders and may be prescribed combination antipsychotics. Aim present study was to evaluate pharmacokinetic interaction between various antiepileptics quetiapine, a second-generation antipsychotic, patients, by using data from therapeutic drug monitoring service. Steady-state plasma concentrations quetiapine were compared patients treated alone (controls, n=35) comedicated val- proic acid (n=19), lamotrigine (n=16), carbamazepine (n=6), topiramate (n=6) oxcarbazepine (n=5). The six groups matched for sex, age daily dose quetiapine. Dose-normalized sig- nificantly lower group than control (p<0.001), while there no differences valproic acid, lamotrigine, or con- trol group. In 5 assessed on off comedication, dose-normalized significantly during therapy (p<0.01). By contrast, appre- ciable changes levels found 8 6 lamo- trigine respectively. These findings confirm that decreases markedly steady-state presumably inducing its CYP3A4-mediated biotransformation. Conversely, concomitant administration doses does not appear affect