Review real-world experience initiating subcutaneous apomorphine hydrochloride injections (Apokyn; APO-SC) without trimethobenzamide premedication.

Trimethobenzamide has been the antiemetic of choice in the United States as premedication for people with Parkinson’s disease (PwP) initiating APO-SC treatment to rapidly manage OFF episodes. However, cessation of US trimethobenzamide manufacture in 2021 resulted in APO-SC initiations being increasingly conducted without antiemetic pretreatment. Further, in 2022, U.S. Prescribing Information for APO-SC was updated to include a flexible dose initiation and titration strategy that advises prescribers to consider initiating at 1.0mg [0.1mL] (instead of 2.0mg [0.2mL]) in the absence of TBZ. The Clinical Educator Program (CEP) is a comprehensive, company-sponsored, U.S. support network available to PwP prescribed APO-SC. Per CEP protocol, clinical educators schedule visits with enrolled PwPs throughout the APO-SC initiation and post-initiation period.

Clinical Educator Time Logs for APO-SC new initiations from 01SEP2022 through 30APR2023 were collected from the CEP database.  Treatment information, including initial dose, and three-month patient outcomes were evaluated and compared with a prior (2019-2021) analysis evaluating initiation with and without trimethobenzamide.

Data were available for 149 unique PwP, all of whom initiated APO-SC without trimethobenzamide. Overall, 62% of PwP initiated APO-SC at a 1.0mg starting dose and 36% initiated at a 2.0mg dose. This contrasts with our 2019-2021 patient cohort where 36% initiated at 1.0mg and 61% initiated at 2.0mg. Lack of antiemetic use did not appear to affect treatment continuation. Overall, 19% of PwP discontinued (for any reason) prior to completing 3 months of treatment, compared with 24.5% in the 2019-2021 cohort. 

Apo-SC is now routinely initiated in the U.S. without antiemetic pretreatment, with most PwP successfully continuing to maintenance therapy. Using a flexible dose initiation and titration strategy, backed by a comprehensive support network such as the CEP, supports successful treatment initiation.