A phase I study to evaluate the effect of high-dose carbidopa on levodopa pharmacokinetics.

ABSTRACT: Levodopa is the gold standard treatment for Parkinson's disease. However, a high unmet medical need exists for longer-lasting oral levodopa formulations to achieve sustained motor improvement with reduced risk of the effect wearing off. In our previous non-clinical studies using rats, more than 3-fold prolongation of the levodopa half-life was achieved when it was combined with a high carbidopa dose. This study aimed to evaluate the effects of high-dose carbidopa on the pharmacokinetics of levodopa. A phase I study was performed to examine the effects of a combination of levodopa, carbidopa, and entacapone in healthy male volunteers. Levodopa and entacapone doses were set at approved dose levels. The carbidopa dose ranged from the approved 10 mg-600 mg. In addition to plasma concentrations

SUBMITTER: Hayashi A 

PROVIDER: S-EPMC12277756 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature