The effect of entacapone on levodopa rate of absorption and latency to motor response in patients with Parkinson disease.
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.
Neurology Clinic, Department of Neurological Sciences, University of Bologna, Bologna, Italy. manuela.contin@unibo.it
Manuela
M
Contin
Paolo
P
Martinelli
Cesa
C
Scaglione
Patrizia
P
Avoni
Fiorenzo
F
Albani
Roberto
R
Riva
Agostino
A
Baruzzi
D000368:Aged; D002396:Catechols / Q000008:administration & dosage / Q000097:blood*; D004347:Drug Interactions / Q000502:physiology; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects* / Q000502:physiology; D007980:Levodopa / Q000008:administration & dosage / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009048:Motor Skills / Q000187:drug effects* / Q000502:physiology; D009570:Nitriles / Q000008:administration & dosage / Q000097:blood*; D010300:Parkinson Disease / Q000097:blood* / Q000188:drug therapy / Q000503:physiopathology; D011930:Reaction Time / Q000187:drug effects* / Q000502:physiology
D002396:Catechols; D009570:Nitriles; D007980:Levodopa; C071192:entacapone