Date of Award


Degree Type

Selective Evidence-Based Medicine Review

Degree Name

Master of Science in Health Sciences - Physician Assistant


Physician Assistant Studies


Objective: "The objective of this selective EBM review is to determine "Is extended-release amantadine efficacious in treating levodopa-induced dyskinesia in Parkinson's disease patients?”

Study Design: A systematic review of three randomized controlled trials (RCT's) that were peer-reviewed and published in English after 2010.

Data Sources: All data sources were discovered in PubMed, NLM Catalog, EMBASE, and CINAHL. All articles were published in English in peer-reviewed journals and selected based on applicability to the clinical question and whether the outcomes were patient-oriented.

Outcome Measured: The primary outcome measure was a change from baseline in the Unified Dyskinesia Rating Scale total scores in Parkinson’s disease patients randomized to Amantadine ER or placebo.

Results: All three studies found that Amantadine ER had a significant treatment effect on levodopa-induced dyskinesia in Parkinson’s disease patients. (Pahwa et al., 2015) study found an NNT of four with a least-square [LS] mean treatment difference of -11.3, 95% confidence interval -19.1 to -3.5], P =0.005. This represents a 27% reduction in UDysRS from baseline compared to placebo. (Pahwa et al., 2017) found an NNT of three with a least-square [LS] mean treatment difference of -7.9, 95% confidence interval, -12.5 to -3.3; P<.001. The study revealed that 51(81%) patients in the Amantadine ER treated group vs. 21(36.2%) patients in the placebo group were assessed as improved in levodopa-induced dyskinesia. Lastly, Oertel et al. found an NNT of three with a least-squares mean treatment difference of -14.4 [95% CI -20.4 to -8.3], P<.0001. The study revealed that 19(51%) in the Amantadine ER treated group and 4(11%) placebo-treated group was assessed as moderately improved in dyskinesia.

Conclusion: All three studies revealed Amantadine ER as an effective treatment option for levodopa-induced dyskinesia in PD patients. Further studies should explore its long-term efficacy as levodopa, and dopaminergic therapy doses increase to compensate for disease progression.