Early factors for predicting discontinuation to subcutaneous Apomorphine infusion in Parkinson's disease: A prospective analysis of the Thai Apomorphine Registry

Abstract

Introduction: Although continuous subcutaneous apomorphine infusion (CSAI) is an effective therapy for Parkinson's disease (PD) with motor fluctuations, data from Asian cohorts is limited. The therapy is often discontinued due to the complexity of its delivery.

Methods: Fifty-one PD patients undergoing CSAI as an add-on therapy were enrolled in the Thai Apomorphine Registry, an electronic database that recorded clinical characteristics and parameters during the 14-consecutive-day titration and long-term follow-up. Factors at the time of titration were documented in order to identify predictors of long-term discontinuation.

Results: Following initiation, PD patients were administered a mean CSAI dose of 5.89 mg/h (SD 1.36) over a mean time of 12.28 h (SD 1.90) each day. The mean follow-up period was 626.2 days (SD 619.17). Significant reductions in UPDRS-I, II, III, and IV scores, total NMSQ score, PDQ-8 score, daily off and dyskinesia hours, Timed Up and Go test, walking step test, levodopa-equivalent daily dose, number of times a day the levodopa was taken versus pre-CSAI values were observed (p < 0.05, each). Thirty-five (68.6%) patients discontinued during the follow-up period. Relative risks of variables recorded at the time of titration that determined discontinuation of CSAI therapy were an absence of full-time caregivers, achieving a daily off hours reduction <3.5 h, and NMSQ scores at the time of CSAI titration ≥9.5 points.

Conclusion: Identifying factors that predict discontinuation of CSAI at the time of its initiation may help physicians to better understand the patient's drug response and how to manage them long-term.

Keywords: Apomorphine therapy; Parkinson's disease; Thai apomorphine registry.