Sildenafil (Viagra) for the Treatment of Dyskinesias in Parkinson's Disease

Study Overview
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Brief Summary
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This study is to determine if Viagra is effective in reducing dyskinesias in patients with Parkinson's Disease.

Detailed Description
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Inclusion Criteria: Diagnosis of idiopathic Parkinson's disease. Age > 40 years. willingness and ability to comply with the study requirements and give informed consent.

Official Title
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A Double-Blind, Placebo-Controlled, Cross-Over Study of Sildenafil (Viagra) for the Treatment of Dyskinesias in Parkinson's Disease

Conditions
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Parkinson's Disease

Intervention / Treatment
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* Drug: sildenafil
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of idiopathic Parkinson's disease, Hoehn and Yahr stage 2.0 to 4.0. Presence of drug-induced dyskinesias Age>40 years. Willingness and ability to comply with the study requirements and give informed consent. Exclusion Criteria: Atypical parkinsonian syndrome due to drugs, metabolic disorders, encephalitis, or degenerative diseases. History of stereotaxic brain surgery. Clinical history of dementia. Known major psychiatric disorder, major depression, schizophrenia. Known alcoholism or substance dependence within previous 12 months. History of major hematological, renal, or hepatic abnormalities. Known coronary artery disease including angina or myocardial infarction within the last 6 months. Significant cardiovascular disease including cardiac failure, unstable angina or life-threatening arrhythmia within the last 6 months. History of stroke within the last 6 months. Abnormal EKG consistent with cardiac ischemia. Treatment with nitrates. Nitrates or any NO donors in any dosage form (oral, sublingual, transdermal, inhalation, or aerosols). Malignant hypertension or SBP . 180 or <90, or DBP .110 or <50. History of priapism. Known history of retinitis pigmentosa. Positive pregnancy test. History of bleeding disorder. Patients with active peptic ulcer disease associated with bleeding. Unwillingness to use adequate contraceptive methods if of childbearing potential. Patients with medical or psychological condition or social circumstances that would impair their ability to participate in the study. Use of Viagra or any experimental drugs within 30 days of screening visit.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Viagra<br>subjects will be randomized to active treatment for 2 weeks, washout for 1 week, then enter the other study arm for two weeks. | Drug: sildenafil<br>* sildenafil 50mg BID for 2 weeks<br>* Other names: Viagra;|
| Placebo Comparator: Placebo comparator<br>subjects will be randomized to placebo treatment for 2 weeks, washout for 1 week, then enter the other study arm for two weeks. | Drug: Placebo<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Duration of Dyskinesia. |  | 2 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percent Change in on Time | on time is the period in which the subject is symptom free. We will track the amount of time the subject is considered symptom free before and after treatment. This value will be represented as a percent change. | 4 weeks | 
| Change in Dose of Anti-parkinsonian Medications |  | 7 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Parkinson's disease, PD, dyskinesia, treatment, motor complications