The Limitations of Dopaminergic Therapies in Advanced Parkinson’s Disease

In advanced Parkinson’s disease (APD), the efficacy of conventional oral and transdermal pharmacological therapies gradually declines and becomes increasingly variable. In such cases, the initiation of device-aided therapies may become necessary. The aim of this study was to describe the final dopaminergic treatment regimens used in a cohort of patients with APD for whom current non-invasive therapies no longer provided adequate symptom control. In this retrospective study, the use of dopaminergic medications was analysed based on final clinical recommendations, including discharge summaries, medical reports, and data retrieved from clinical registries. During the four-year study period, levodopa-carbidopa intestinal gel (LCIG) therapy was initiated in 72 patients with APD. The mean age of the cohort was 65.67 ± 8.51 years (mean ± SD), and the mean disease duration was 10.14 ± 4.01 years. The mean duration of levodopa therapy was 9.02 ± 3.81 years. Patients received relatively high doses of levodopa (898 ± 266 mg/day), administered in 5.26 ± 0.63 daily doses (range: 5–7 administrations per day). The majority of patients (83%) were also treated with dopamine agonists: pramipexole (n = 17), ropinirole (n = 15), and rotigotine transdermal patch (n = 28). Rasagiline was prescribed to 62.5% of patients (n = 45). An apomorphine pen was used by nine patients. Amantadine was prescribed to 20 patients, while entacapone was included as an adjunct to levodopa replacement therapy in 40 patients (56%). The dopaminergic treatment regimens used prior to the initiation of device-aided therapy in patients with APD were more complex than those previously reported in the literature. We believe that analyses of this kind may help practicing neurologists recognize the limitations of conventional dopaminergic therapies and facilitate the timely referral of patients with APD for evaluation of eligibility for available device-aided treatment options.