A critical review of apomorphine hydrochloride sublingual film for the treatment of Parkinson's disease 'OFF' episodes.

Introduction: Parkinson's disease (PD) is a neurodegenerative disorder defined by its motor features. Levodopa therapy is the gold standard therapy, but over time, response is impeded by the development of motor fluctuations, including 'off' episodes where PD symptoms reemerge. Sublingual apomorphine offers a new, novel, and effective therapy developed for treatment of 'off' episodes. Areas covered: Apomorphine is an old dopamine agonist developed as a subcutaneous injectable rescue therapy for 'off' periods in PD that was approved in the United States in 2004. We will discuss its history, chemistry and clinical use. We will also cover the recent development and approval of sublingual apomorphine film that offers a novel formulation and provides effective treatment for 'off' episodes including results of the phase 3 randomized, double-blinded, placebo-controlled study. Oral mucosal side effects, which were mild to moderate and reversible in most patients experiencing them, will be discussed. Expert opinion: The new sublingual apomorphine is safe and effective for relief of 'off' periods that impact quality of life. Its ease of use will be beneficial to those with needle phobia and device challenges with currently available injectable and inhaled therapeutics. Side effect profile is an improvement from previous attempts at sublingual formulation.