Dose-response relationship of levodopa with dyskinesia in Parkinson's disease: A systematic review and meta-analysis.

Despite existing evidence linking dyskinesia to levodopa, the primary treatment for Parkinson's, the dose-response relationship and risk factors remain uncertain. In this study, the risk for dyskinesia in patients with Parkinson's disease receiving levodopa was evaluated via meta-analysis and meta-regression approaches to examine dyskinesia risk factors more reliably and improve treatment strategies and patient care. The PubMed and Embase databases were searched to identify randomized controlled trials comparing levodopa with other anti-Parkinson's drugs published in English before June 31, 2023. The primary outcome was dyskinesia, and a risk of bias assessment was performed. In total, 24 studies met the inclusion criteria; 21 had a low risk of bias, and 3 had a high risk of bias. These studies included 4698 patients with Hoehn and Yahr Grade I-III Parkinson's disease. Our meta-analysis showed that the risk of dyskinesia was higher for levodopa than for other anti-Parkinson's drugs (odds ratio: 2.52 [95% confidence interval: 1.84-3.46]). Dyskinesia was not related to age (slope coefficient: 0.185 [0.095]; P = 0.061), disease duration (slope coefficient: 0.011 [0.018]; P = 0.566), or treatment duration (slope coefficient: 0.008 [0.007]; P = 0.216). The mean levodopa equivalent dose (slope coefficient: 0.004 [0.001]; P = 0.001) in the experimental group and the differences in drug doses between the experimental and control groups were correlated with the risk of dyskinesia. Results of randomized controlled trials supported an association between the levodopa dose and dyskinesia in patients with Parkinson's disease. Compared with levodopa users, users of other anti-Parkinson's drugs had a lower incidence of dyskinesia. Age, disease duration, and treatment duration were not correlated with dyskinesia. These findings suggest that anti-Parkinson's drugs other than levodopa, particularly in cases of early-stage Parkinson's disease, should be considered to reduce the risk of dyskinesia.

[Systematic review and screening of basic Chinese herbs for traditional Chinese medicine compounds combined with levodopa medicine in treatment of Parkinson's disease].

To systematically evaluate the efficacy of traditional Chinese medicine(TCM) compounds combined with levodopa medicine in the treatment of Parkinson's disease(PD), and screen basic herbs to provide certain evidence-based medical proof and program for better guidance on clinical drug use. Six databases were searched to screen out the randomized controlled trial on the TCM compounds combined with levodopa medicine in the treatment of PD. Literature quality of the included studies was evaluated by improved Jadad rating scale, and the Meta-analysis was performed by RevMan 5.3 software. After the data of the basic TCM compounds involved were sorted out, the strong association rules were found by using Apriori algorithm of SPSS Modeler 18.0 software, and then the basic herbs for the treatment of PD could be picked out. A total of 20 studies were eventually included, involving 1 784 patients. Ten studies were of high-quality literature, Jadad score≥4 points. Meta-analysis showed that efficacy of TCM combined with levodopa medicine was better than levodopa medicine alone in lowering Unified Parkinson's Disease Rating Scale(UPDRS) score: UPDRS Ⅰ(MD=-0.43, 95%CI[-0.62,-0.24], P<0.000 1), UPDRS Ⅱ(MD=-2.72, 95%CI[-3.24,-2.21], P<0.000 01), UPDRS Ⅲ(MD =-1.97, 95%CI[-2.69,-1.25], P<0.000 01), UPDRS Ⅳ(MD=-0.28, 95%CI[-0.46,-0.11], P=0.002). And the improvement in UPDRS score reduction rate of TCM combined with levodopa medicine was better than that in levodopa medicine alone: effective rate(OR=4.81, 95%CI[3.50, 6.62], P<0.000 01). Data mining results showed that the basic prescription for treating PD consisted of Paeoniae Radix Alba-Rehmanniae Radix Praeparata-Gastrodiae Rhizoma in general. According to each part of UPDRS, the basic prescription for treating mentation, behavior and mood(UPDRS Ⅰ) consists of Paeoniae Radix Alba-Rehmanniae Radix Praeparata-Glycyrrhizae Radix et Rhizoma Praeparata Cum Melle, Among which Glycyrrhizae Radix et Rhizoma Praeparata Cum Melle might have unique efficacy. The basic prescriptions for treating UPDRS Ⅱ and UPDRS Ⅲ consisted of Paeoniae Radix Alba-Rehmanniae Radix Praeparata, or Chuanxiong Rhizoma-Angelicae Sinensis Radix(two drug combinations). However, in the treatment of UPDRS Ⅳ, the drugs were scattered. But due to the limitations in the quantity and quality of clinical studies, the results obtained still need further research and clinical confirmation of its efficacy.