Topiramate as an Adjunct to Amantadine in the Treatment of Dyskinesia in Parkinson's Disease

Study Overview
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Brief Summary
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The study will involve an eighteen-week, double-blind, placebo-controlled parallel designed comparison between add-on topiramate and add-on placebo to stable treatment with amatadine in the treatment of Parkinson's disease (PD) patients who continue to have dyskinesia on amantadine.

Detailed Description
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We conducted a randomized placebo controlled trial of topiramate in PD dyskinetic subjects already on amantadine but with continuing dyskinesia. Topiramate or placebo was introduced in blinded fashion with a gradual titration (topiramate 25-150 mg/d) over 6 weeks and then a maintenance period of 8 weeks. The primary outcome of interest was change from baseline to end of study in total Unified Dyskinesia Rating Scale (UDysRS) score using Intention to Treat analysis.

Official Title
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Topiramate as an Adjunct to Amantadine in the Treatment of Dyskinesia in Parkinson's Disease

Conditions
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Idiopathic Parkinson's Disease, Drug Induced Dyskinesia

Intervention / Treatment
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* Drug: Topiramate
* Drug: Placebo
* Drug: Amantadine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Parkinson's disease patient, defined by United Kingdom (UK) Brain Bank criteria Current age between 30-90 Clinically pertinent dyskinesias defined by Clinical Global Impression - Severity (CGI-s) score (see attachment) > 3 (mild) established by clinician's total assessment of patient including objective observation during the screening process. * Stable doses of all antiparkinsonian medications for at least 4 weeks Stable treatment with at least 200 mg amantadine for at least 4 weeks. Presence of a caregiver willing to participate in the study In the opinion of the enrolling investigator, the subject will be able to maintain current dosing schedule of antiparkinsonian drugs for the duration of the trial. Subjects must be free of dementia, depression and psychosis as determined by clinical examination. The subject must be willing to participate in all study related activities and visits. Exclusion criteria: Any subjects with clinical evidence suggestive of an atypical or secondary form of Parkinson's Disease Any subject who, in the opinion of the Principal Investigator, has a concomitant medical illness which would preclude them from being treated with amantadine, Any subject who, in the opinion of the Principal Investigator, will be unable to maintain current stable dosing of their anti-parkinsonian medications for the duration of the trial, Any subject with evidence for dementia, depression, or psychosis, as determined by clinical examination. Any subject who has not signed informed consent, or unable or unwilling to participate in all of the study related activities.

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Topiramate<br>Topiramate as adjunct to amantadine. | Drug: Topiramate<br>* Topiramate as adjunct to amantadine<br>* Other names: Topamax;Drug: Amantadine<br>* Existing treatment for all participants<br>* Other names: Symmetrel;|
| Placebo Comparator: Placebo (sugar pill)<br>Placebo | Drug: Placebo<br>* Placebo control<br>* Other names: sugar pill;Drug: Amantadine<br>* Existing treatment for all participants<br>* Other names: Symmetrel;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The Unified Dyskinesia Rating Scale (UDysRS) | The Unified Dyskinesia Rating Scale (UDysRS) will be the primary outcome measure for this study. This choice is based on the outcome of the Validation of Dyskinesia Rating Scales study. In this study, the UDysRS was identified as the most sensitive scale to detect change in dyskinesia in an 8-week, double-blind, placebo-controlled trial of amatadine. The UDysRS utilizes rater information, patient self-report and objective measures of dyskinesia to provide assessments of impairment and disability due to dyskinesia. Score ranges are 0-108 with higher scores representing more severe impairment. | Change from baseline to week 14 (end of study) on the Unified Dyskinesia Rating Scale | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Parkinson's disease, dyskinesia, Indonesia, amantadine