Initiating Apomorphine Therapy Without Antiemetic Pretreatment: Real-World Data From a Nurse-led Parkinson Disease Support Program

BACKGROUND: Trimethobenzamide has been the antiemetic of choice in the United States for people with Parkinson disease initiating subcutaneous apomorphine injection (SC-APO) therapy to rapidly manage OFF episodes. Following a cessation of trimethobenzamide production in 2021, SC‑APO was increasingly initiated without antiemetic pretreatment. METHODS: Data from the SC-APO Clinical Nurse Navigator support program were analyzed for new patient starts between January 2019 and March 2024, spanning periods before and after trimethobenzamide absence and SC-APO labeling changes. SC-APO starting dose patterns and 90-day treatment continuation were compared between patients who started with and without antiemetic pretreatment. RESULTS: Among 2634 patients, SC-APO initiations without trimethobenzamide increased from 32.8% before cessation of production (2019-2020) to nearly 100% by the end of 2021. During 2021, most prescribers (56.7%) continued to use the 0.2 mL (2.0 mg) starting dose; following a 2022 labeling update, use of the 0.1 mL (1.0 mg) starting dose increased to 86% by early 2024. The 90-day SC-APO continuation rates increased from 75.4% when used with trimethobenzamide pretreatment to 83.1% without it. CONCLUSION: SC-APO is now routinely started without antiemetic pretreatment, with higher overall rates of early treatment continuation. Flexible starting doses and titration, together with nurse‑led patient education and support, may facilitate successful treatment initiation and continuation in contemporary clinical practice.