BIPARK-1 was a Phase III, randomised, double-blind placebo- and active-controlled study of opicapone as an adjunct to levodopa therapy in which 600 patients with Parkinson's disease and motor fluctuations received once-daily opicapone (5 mg, 25 mg, or 50 mg), placebo, or 200 mg doses of the COMT inhibitor
entacapone for 14 to 15 weeks.
(20) As noted above, enta-capone is a COMT inhibitor
; it increases the plasma half-life of levodopa and decreases variations in peak-trough levels.
Responsiveness was obtained from two clinical trials for WOQ-19 comparing add-on therapy with entacapone (a COMT inhibitor
For example, the COMT inhibitor
, tolcapone (Tasmar[R]), has been withdrawn from use in several countries (excluding the US) because it can increase liver problems by as much as 100%.
While the studies carried out in Europe have proved the effectiveness of this COMT inhibitor
in L-dopa-induced hyperhomocysteinemia, no correlation has been demonstrated in studies conducted in the USA (2,22,24).
(1,11) The plasma half-life of levodopa increases approximately 50% when administered with a COMT inhibitor
, consequently allowing lower levodopa doses to achieve desired effects.
When the other available COMT inhibitor
, entacapone (Comtan), is given as 200 mg with each dose of Sinemet, it reduces L-dopa peaks.
A new COMT inhibitor
, entacapone (Comtess[R]), has recently received approval in the United States.
According to BIAL, ONGENTYS (opicapone) is a novel, once-daily, peripherally-acting, highly-selective COMT inhibitor
proposed for use as adjunct therapy to levodopa in Parkinson's patients.
Adding a dopamine agonist or a COMT inhibitor
to the regimen of a patient who is already on levodopa can cause dyskinesia and hallucinations, particularly in advanced patients.
In advanced disease, motor complications can also be managed by augmenting levodopa therapy with a dopamine agonist, MAO-B inhibitor, or COMT inhibitor
(7,8) (SOR: A).