Apomorphine injections: Predictors of initial common adverse events and long term tolerability

Background: Apomorphine injections effectively abort "off" episodes in Parkinson's disease (PD). However, their use is limited by actual and perceived adverse events (AE). To our knowledge, no study has evaluated for predictors of these problems. Objectives: To assess predictors of initial common AE and long-term tolerability of apomorphine injections in PD. Methods: We prospectively monitored for AE in 28 consecutive PD patients receiving initial apomorphine injections. Sequential visual analogue scale scores for nausea and in standing systolic blood pressure drops at baseline (mean of 2 assessments), 10, 20, and 40. min post-injection were acquired. Assessed historic variables included patient demographics and clinical data, treatment histories, previous AE to other dopaminergic treatments and whether patients received the recommended three day pre-treatment dose of trimethobenzamide. We also correlated the L-dopa equivalent doses with apomorphine dose needed to turn "on" Results: No patient demographic or previous history of dopaminergic AE predicted nausea, except for baseline pre-injection nausea that day at baseline. Three days of trimethobenzamide, as recommended, was actually associated with more nausea than a single dose or no dose, even though a lack of association after matched analysis was found. A younger patient age was associated with hypotension. L-dopa equivalent dose modestly correlated with final apomorphine dose to turn "on" Conclusion: A previous history of nausea and hypotension, and older age should not dissuade a trial of apomorphine if clinically justified. A three day pre-treatment dose of trimethobenzamide, as recommended in the United States, does not reduce nausea.