Parkinson's Disease Isradipine Safety Study

Isradipine safety profile Isradipine, FDA approved for treatment of hypertension since 1990, has a well established data on its efficacy and safety in the hypertensive population (see package insert, Appendix 3). The side effect profile of isradipine is related to the primary mechanism of action of the agent as a vasodilator of the vascular smooth muscles and myocardium, and includes hypotension, bradycardia, weakness, and syncope. As per package insert, the most common adverse effects are headache (13.7% with active treatment versus 14% placebo), dizziness (7.3 vs 4.4) and peripheral edema as reflection of the vasodilatory effect which is dose dependent with incidence of about 3.5% at 5 mg, 8.7% at 10 mg and 8.5% at 20 mg. Of note the incidence of edema is substantially lower compared to CR preparation (9:13:36% for the respective doses). The other side effects include angina, asthenia, flushing, heart failure, and palpitations. According to the package insert, the adverse effects are usually not serious, dose dependent, and respond well to dose reduction or discontinuation of therapy. Isradipine has no effect on atrioventricular or sinoatrial conduction. The only absolute contraindications for isradipine are hypersensitivity to DHP compounds and hypotension defined as systolic blood pressure below 90 mm Hg. Until our studies, isradipine has not been tested in the PD population.