Caffeine as a Therapy for Parkinson's Disease

Exclusion Criteria

• •1. Caffeine intake \>150 mg per day (i.e. more than one cup of filtered coffee per day) or prescribed adenosine antagonists - caffeine intake will be measured by a standardized intake questionnaire. Intake will be converted into estimated caffeine mg dose by standard caffeine-content charts.
• •2. Active peptic ulcer disease, or symptomatic gastroesophageal reflux disease.
• •3. Supraventricular cardiac arrhythmia (such as atrial fibrillation or atrial flutter) - Electrocardiogram will be measured at baseline to rule out supraventricular tachycardia.
• •4. Uncontrolled hypertension - systolic bp \>170 or diastolic bp \>110 on two readings.
• •5. Pre-menopausal women who are not using effective methods of birth control
• •6. Cognitive impairment, defined as MoCA \<23/30.
• •7. Moderate-Severe Depression, as defined by a Beck Depression Inventory score of \>19.
• •8. Changes to antiparkinsonian medication in the last 3 months, or changes to antiparkinsonian medication are anticipated during the next six months.
• •9. Current use of lithium or clozapine (pharmacokinetic interactions).