8b85b910_d_s_Flow___Scientific_American__2
[0] Calcium channel blockers [1] Nifedipine [3] Some scientists propose that an excess of calcium channels in the brain can contribute to Parkinson’s disease, as too much calcium can be toxic to dopamine neurons. Epidemiological studies hint that taking calcium channel blockers that cross the blood brain barrier (not all do) reduces the likelihood of developing Parkinson’s. [2] 
Calcium channel blockers prevent calcium ions from entering cell membranes in the heart and arteries, a process that normally signals the blood vessels to contract. By reducing the force of contraction, these drugs allow the heart to pump blood with less effort.
Common Prescription Drugs Alter Blood’s Flow - Scientific American
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