The Effect of Entacapone on Levodopa Rate of Absorption and Latency to Motor Response in Patients With Parkinson Disease

Abstract

Objective: 

The aim of the study was to explore the potential effect of the catechol-O-methyltransferase inhibitor entacapone coadministration on the rate of absorption and matched latency to motor response of an oral test dose of levodopa/benserazide in the treatment of Parkinson disease (PD).

Methods: 

Fourteen PD patients (Hoehn and Yahr stages 2-2.5) entered the study protocol. They underwent an oral levodopa instrumental kinetic-dynamic test on 2 occasions, 4 weeks apart, according to an intrasubject open comparative design: at the first examination, while receiving their usual levodopa/benserazide therapy, and at the second one after a 4-week entacapone (200 mg) dosing concomitantly with usual first morning levodopa/benserazide intake.

Results: 

Entacapone coadministration was associated with a median 15-minute lengthening (P < 0.05) of time to peak levodopa plasma concentration compared with levodopa/benserazide alone but failed to have a statistically significant effect on matched latency to drug motor effect. Levodopa peak plasma concentration was nearly identical in the 2 treatments.

Conclusions: 

Overall, the delayed latency to single-dose peak plasma levodopa concentration on entacapone cotreatment was modest and of negligible clinical significance in a cohort of moderately affected PD patients.