Numerous epidemiological studies have demonstrated that the use of calcium-channel blockers - a class of medication used for controlling blood pressure - are associated with a reduced risk of developing Parkinson’s. In addition, pre-clinical lab experiments have provided data suggesting calcium-channel blockers have neuroprotective properties in models of Parkinson's. These results led to the initiation of a large clinical trial (the STEADY-PD study) of the calcium-channel blocker, isradipine, in people with Parkinson's.

The results of the Phase lll STEADY-PD clinical trial have now been published. The study involved 300 people with newly diagnosed Parkinson's (most within 12 month of diagnosis) who were treated with isradipine (or a placebo) twice daily for a period of 36 months. None of the participants were taking any dopamine-based medication at the start of the trial, and the study was investigating whether isradipine would slow down the initial progression of the symptoms of Parkinson's as determined by clinical assessment using the Unified Parkinson's Disease Rating Scale (UPDRS) Part 1-3. Unfortunately, the results of the study suggest that long-term treatment with isradipine did not slow the clinical progression of early-stage Parkinson's.

Read the results abstract.