Modeling of the LDL cholesterol-lowering effect of atorvastatin in Korean dyslipidemic patients and non-patient volunteers

Objective The aim of this study was to develop a longitudinal pharmacodynamic model describing the time-courses of low-density lipoprotein cholesterol (LDL) profiles during and after atorvastatin treatment in Korean dyslipidemic patients and non-patient volunteers. Methods 15 dyslipidemic patients and 11 non-patient volunteers with no prior therapy participated in a parallel, 2-step dose escalation study. Subjects received atorvastatin doses ranging from 10 to 80 mg for 42 days (dyslipidemic patients) or 10 mg for 21 days (non-patient volunteers). Plasma samples were collected before and during the treatment period and up to 2 weeks after the last administration. A population pharmacodynamic model was built using the NONMEM software package. An indirect response model consisting of production in hepatocyte and elimination from plasma stimulated by atorvastatin described the LDL time-course. Results The typical population value of the estimated dose producing 50% of maximal stimulation on LDL elimination (SD50) for dyslipidemic patients was 11.9 mg, which was about 6 times higher than that of non-patient volunteers (2.0 mg). Conclusion A longitudinal population pharmacodynamic model for the LDL-lowering effect of atorvastatin in both dyslipidemic patients and non-patient volunteers was developed. This could help guide optimal therapies according to the target population.