EFFECT OF ENTACAPONE, A PERIPHERALLY ACTING CATECHOL-O-METHYLTRANSFERASE INHIBITOR, ON THE MOTOR RESPONSE TO ACUTE TREATMENT WITH LEVODOPA IN PATIENTS WITH PARKINSONS-DISEASE

Catechol-O-methyltransferase (COA IT) inhibitors may be useful in the treatment of Parkinson's disease by improving the bioavailability of l evodopa and by prolonging its effects. Entacapone (OR-611), a novel CO MT inhibitor, which does not cross the blood brain barrier, was assess ed in 12 patients with Parkinsons disease and motor fluctuations in a randomised, double-blind, cross-over, single dose study. The magnitude and duration of the therapeutic response to a single dose of 200 mg l evodopa/50 mg carbidopa was evaluated after concomitant placebo, or 20 0 or 800 mg entacapone. A significant increase in the duration of the motor response to levodopa was seen when 200 mg entacapone was given w ith levodopa/carbidopa. Plasma levodopa concentrations were increased with both doses of the COMT inhibitor. The latency to onset of motor r esponse did not differ significantly between active drug and placebo. Entacapone may prove useful in prolonging the duration of the benefit obtained from individual doses of levodopa.