Levodopa alone compared with levodopa-sparing therapy as initial treatment for Parkinson's disease: a meta-analysis

To assess the long-term use of l-dopa alone vs l-dopa-sparing therapy, as initial treatment, provides the most efficient long-term control of symptoms and best quality of life for people with early Parkinson's disease (PD). PubMed; Google scholar; Cochrane Central Register of Controlled Trials and the Web of Science were searched for randomised, placebo-controlled trials (RCTs) on l-dopa alone and l-dopa sparing as initial treatment in early PD patients. We used a random effects model rather than a fixed effects model because of this takes into account heterogeneity between multi-studies. Eleven RCTs were included. The results showed that l-dopa alone could evidently improve the UPDRS part I (p = 0.005), part II (p < 0.0001), part III (p < 0.0001) and UPDRS total score (p = 0.004) compared with l-dopa-sparing therapy in PD patients. Meanwhile, a reduced risk of dyskinesia (p < 0.0001, RR = 1.88, 95 % CI 1. 37-2.59) and wearing-off phenomenon (p < 0.00001, RR = 1.36, 95 % CI 1. 20-1.55) in patients treated initially with l-dopa-sparing therapy compared to l-dopa has been consistently reported. What is more, we found more patients on al-dopa-sparing therapy were more than triple as likely to discontinue treatment prematurely due to adverse events than l-dopa treatment patients (43.7 vs 15.8 %). l-Dopa alone is the most effective medication available for treating the motor symptoms of PD patients, despite the greater incidence of involuntary movements. Meanwhile, more patients on dopamine agonists or MAOBI were more likely to discontinue treatment prematurely than l-dopa alone treatment patients within the long follow-up period.