Influence of Piribedil (Clarium®) on Vigilance and Cognitive Function in Patients With Parkinson's Disease Compared to Other Non-Ergot Dopamine Agonists (PIVICOG-PD)

Inclusion Criteria:

• Male or female Caucasian patients aged 35 to 80 years;
• Patients with idiopathic Parkinson's disease;
• Hoehn & Yahr stages 1 to 4;
• Stable medication with anti-parkinsonian medication, including stable treatment with pramipexole or ropinirole, for at least 4 weeks prior to Screening;
• Significant daytime sleepiness: Epworth Sleepiness Scale score equals or is higher than 11 under previous therapy with pramipexole or ropinirole;
• Patients who have read and understood the patient information sheet and have provided a signed written informed consent form;
• Patients are considered to be compliant to the study regimen.

Exclusion Criteria:

• Treatment of Parkinson's disease with any dopamine agonist other than pramipexole or ropinirole within 4 weeks prior to Screening;
• Known hypersensitivity to Clarium® or its excipients;
• Patients with daytime sleepiness caused by other factor's than Parkinson's disease, i.e., idiopathic narcolepsy, shift work, severe alcohol abuse, obstructive diseases, sleep apnea syndrome, or Periodic limb movement disorder;
• Secondary and atypical Parkinson syndrome;
• Depression (Beck Depression Inventory score higher than 16);
• Dementia (Mini-Mental State Examination score equals or is lower than 24);
• Severe disability in extremities which could influence clinical assessments;
• Clinically significant disease concerning the lung, liver or kidney;
• Any acute or chronic infection that may influence the outcome of the study;
• Cardiovascular shock;
• Acute myocardial infarction;
• Congestive heart failure NYHA class III or IV;
• Uncontrolled arterial hypertension (diastolic blood pressure equals or is higher than 105 mmHg) or clinically relevant hypotension;
• Evidence of clinically active cancer;
• Color vision defect that may have impact on assessment of FWIT;
• History of substance abuse;
• Intake of benzodiazepines (or derivates) if not at stable dose for at least 4 weeks prior to Screening; intake of antiallergic agents (H1 receptor antagonists, except selective, non-sedating H1-antihistamines, e.g. loratadine and others), substances with psychostimulant properties (e.g., amphetamine, modafinil), or antidepressants if not at stable dose for at least 2 months prior to Screening;
• Current treatment with neuroleptic agents (except for clozapine);
• Female patients who are pregnant or lactating;
• Female patients of childbearing potential who do not use a highly effective method of birth control (failure rate less than 1% per year when used consistently and correctly), e.g., implants, injectables, combined oral contraceptives in combination with a barrier method, some intrauterine contraceptive devices, sexual abstinence, or a vasectomized partner;
• Mental condition rendering the patient unable to understand the nature, scope and possible risks of the study;
• Patient has a history of or is suspicious of unreliability, poor co-operation or non-compliance with medical treatment;
• Patients are currently or previously (within the last 28 days) participating in another study of an investigational drug;
• Patients who were previously enrolled in this study;
• Patients with known Hepatitis B or C or HIV infection;
• Patients who are employees of the sponsor or patients who are employees or relatives of the investigator.