Population pharmacodynamic modeling of levodopa in patients with Parkinson's disease receiving entacapone

A population pharmacodynamic model for levodopa was built that took into account interindividual and intraindividual variability. The main finding was that entacapone does not alter the concentration-effect curve of levodopa, suggesting that entacapone acts at the level of peripheral pharmacokinetics of levodopa and that plasma levels of 3-O-methyldopa have a negligible role in the pharmacodynamics of levodopa.