©© 2009 American College of Clinical Pharmacology, Inc.
The Journal of Clinical Pharmacology, 10.1177/0091270009343694
Population Pharmacokinetics of Perphenazine in Schizophrenia Patients From CATIE: Impact of Race and Smoking
Yuyan Jin 1*,
Bruce G. Pollock 2,
Kim Coley 1,
Del Miller 3,
Stephen R. Marder 4,
Jeff Florian 1,
Lon Schneider 5,
Jeff Lieberman 6,
Margaret Kirshner 1,
and
Robert R. Bies 1
1 University of Pittsburgh
2 University of Toronto
3 University of Iowa
4 UCLA School of Medicine
5 University of Southern California, School of Medicine
6 Columbia University Medical Center
* To whom correspondence should be addressed. E-mail: yuj4{at}pitt.edu.
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Abstract |
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The goal of the study was to characterize population pharmacokinetics (PPK) for perphenazine in patients with schizophrenia from the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE). Patients (n = 156) received 8 to 32 mg of perphenazine daily for 14 to 600 days for a total of 421 plasma concentrations measurements. Nonlinear mixed-effects modeling was used to determine PPK characteristics of perphenazine. One- and 2-compartment models with various random effect implementations and mixture distributions were evaluated. Objective function values and goodness-of-fit plots were used as model selection criteria. Age, weight, sex, race, smoking, and concomitant medications were evaluated as covariates. A 1-compartment linear model with proportional error best described the data. The population mean clearance and volume of distribution for perphenazine were 483 L/h and 18 200 L, respectively. Race and smoking status had significant impacts on perphenazine clearance estimates. In addition, the estimated population mean clearance was 48% higher in nonsmoking African Americans than in nonsmoking other races (512 L/h vs 346 L/h). Active smokers eliminated perphenazine 159 L/h faster than nonsmokers in each race. Clearances for smoking African Americans versus smokers in other races were 671 L/h versus 505 L/h, respectively.