Opicapone is a long-acting, third generation selective catechol‐o‐methyl transferase (COMT) inhibitor, which became available in Europe in 2016 and is indicated as adjunctive treatment to levodopa in people with Parkinson's disease (PwP) who experience motor fluctuations (Scott 2021; Leta et al. 2020). This evidence concerns the gene COMT and Parkinson disease.