Safety and Efficacy of Levetiracetam for the Management of Levodopa- Induced Dyskinesia in Patients with Parkinson’s Disease: A Systematic Review

Background: Levetiracetam, a novel antiepileptic drug, has shown antidyskinetic effects in experimental animal models of Parkinson's disease (PD). The tolerability and efficacy of levetiracetam in reducing the levodopa-induced dyskinesia (LID) in PD patients have not been established. Therefore, this study aims to synthesize evidence from published prospective clinical trials about the efficacy of levetiracetam for the management of LID in PD patients. Methods: We followed the PRISMA statement guidelines during the preparation of this systematic review. A computer literature search of PubMed, EBSCO, Scopus, MEDLINE, and the web of science was carried out. We selected prospective clinical trials assessing the anti-dyskinetic efficacy of levetiracetam for treating LID in patients with PD. The Abnormal Involuntary Movement Scale (AIMS), Clinical Global Impression Score (GCI), UPDRS III, and UPDRS IV were considered as the primary outcome measures; their data were extracted and reviewed. Results: Our review included seven clinical trials with a total of 150 patients. Of them, three studies were randomized controlled trials, and the remaining were open-label single arm trials. Four studies reported poor tolerability of the levetiracetam with mild anti-dyskinetic effects. Levetiracetam slightly improved the UPDRS-IV and AIMS scores with small effect size. In the remaining three studies, levetiracetam failed to exhibit any anti-dyskinetic effects. Conclusion: Current evidence does not support the efficacy of the levetiracetam for treating LID in PD patients, however, due to the limited number of published randomized control trials (RCTs), further RCTs are required.