Effect of Carbidopa Dose on Levodopa Pharmacokinetics With and Without Catechol-O-Methyltransferase Inhibition in Healthy Subjects.

Increasing carbidopa doses significantly increased the exposure and reduced the fluctuation of IR levodopa in plasma during simultaneous COMT inhibition with entacapone. Theoretical pharmacokinetic simulations suggested that the plasma profile of oral IR levodopa can be even further improved by optimizing AADC and COMT inhibition.