Long-term safety, discontinuation and mortality in an Italian cohort with advanced Parkinson's disease on levodopa/carbidopa intestinal gel infusion

Introduction Levodopa/carbidopa intestinal gel (LCIG) is an effective treatment in patients with advanced Parkinson's disease (PD) with consolidated evidence of clinical efficacy. However, only few studies have assessed long-term safety, causes of discontinuation, mortality, and relative predictors. Methods We conducted a retrospective analysis of 79 PD patients treated with LCIG between 2005 and 2020 in two Italian Neurological Centers, recording all adverse events (AEs), including weight loss (WL). Kaplan-Meier curve was used to estimate the time to discontinuation and survival. Cox proportional hazard model was employed to identify predictors of discontinuation and mortality, while Pearson's correlation was used to analyze predictors of WL. Results The average follow-up was 47.7 +/- 40.5 months and the median survival from disease onset was 25 years. There were three cases of polyradiculoneuropathy Guillain-Barre syndrome-like, all occurred in the early years of LCIG treatment. Twenty-five patients died (32%), 18 on LCIG (including one suicide) and seven after discontinuation. The mean WL was 3.62 +/- 7.5 kg, which correlated with levodopa dose at baseline (p = 0.002), levodopa equivalent daily dose (LEDD) baseline (p = 0.017) and off-duration (p = 0.0014), but not dyskinesia. Peristomal complications emerged as a negative predictor of discontinuation (p = 0.008). Conclusions LCIG has a relatively satisfactory long-term safety profile and efficacy and a relatively low rate of discontinuation. Peristomal complications may represent a predictor of longer duration of therapy. According to the mortality analysis, LCIG patients show a long lifespan. Delaying the initiation of LCIG does not affect the sustainability of LCIG therapy.