Continuous subcutaneous apomorphine infusion (CSAI) is an effective therapy for Parkinson's disease (PD) patients with motor complications. Whether CSAI should be used in association or in monotherapy to prevent any pulsatile stimulation due to oral treatments remains unclear.

This study aimed to evaluate the feasibility, efficacy, and tolerance of CSAI monotherapy compared to its use in combination therapy.

We retrospectively collected the clinical characteristics of PD patients treated with CSAI between 2007 and 2023, before the introduction of CSAI (M0) and after six months of CSAI (M6). We identified the proportion of patients who had CSAI on monotherapy at M6, and collected data on motor symptoms, side effects, and treatment doses in patients treated by monotherapy versus in association.

Of 117 PD patients treated with CSAI between 2007 and 2023, 21 (17.9%; 95%CI: 11.5 to 26.1) were on monotherapy at M6. Monotherapy patients were more likely to be female and had lower baseline levodopa-equivalent doses. Dyskinesia duration at M6 was lower in this group ( P = 0.04) without significant differences in “off” duration, MDS-UPDRS III scores, or side effects compared to those receiving combination therapy. Patients with monotherapy were more frequently treated with continuous 24-hour CSAI and had higher daily apomorphine doses.

CSAI monotherapy is a feasible option for PD patients requiring continuous dopaminergic stimulation, offering improved dyskinesia control with similar efficacy and tolerability to combination therapy. Further studies are needed to determine patient selection for CSAI monotherapy, the long-term benefits obtained and broaden its clinical application.