INTRODUCTION: Opicapone is a third generation, highly potent and effective catechol O‑methyltransferase (COMT) inhibitor that optimizes the pharmacokinetics and bioavailability of L-DOPA therapy. AREAS COVERED: In this review, the authors describe the preclinical and clinical development of opicapone. In PD patients with motor fluctuations, once daily opicapone administration was well-tolerated and consistently reduced OFF-time and increased ON-time without increasing the frequency of troublesome dyskinesia, and these benefits were maintained over at least a year of continued open-label therapy. EXPERT COMMENTARY: With its convenient once-daily regimen, adjunct opicapone should be considered as an effective option for use in L-DOPA treated PD patients experiencing motor fluctuations
