Table 4.

Clinical studies for PD treatment targeting VGCCs.

Disorder and Ca2+ Channel Blocker	Population and Sample Size	Study Design	Results	Refs.
PD, isradipine	Subjects with early idiopathic PD, n = 336	Phase 3, randomized, parallel assignment, double masking, the primary purpose of treatment	↓ disability from PD was observed.	[151]
PD, isradipine	Patients with idiopathic PD, n = 31	Phase 2, single group assignment, open-label, dose-escalation, safety and tolerability	No tolerability differences between isradipine treatment or not treatment with dopaminergic medications. Isradipinehad no effect on PD motor disability. The main adverse effects were: headache, dizziness, and peripheral edema.	[149]
PD, isradipine	Subjects with early idiopathic PD, n = 99	Phase 2, randomized, parallel assignment, double masking, the primary purpose of treatment	Isradipine at the dose of 10 mg daily was the maximal tolerable dosage. Adverse events were: peripheral edema and dizziness.	[150]
PD, isradipine	Patients with early-stage PD (duration <3 years) who were not taking dopaminergic medications, n=336	Phase 3 is a multicenter, randomized, parallel-group, double-blind, placebo-controlled trial.	Long-term treatment with immediate-release isradipine did not slow the clinical progression of early-stage PD.	[153]
PD, isradipine	Subjects with early idiopathic PD, n = 417	Phase 3, multicenter, randomized, double‐blind, placebo‐controlled trial	Isradipine plasma exposure did not affect clinical assessment measures of PD severity. Yet, isradipine exposure decreased the risk of needing anti-parkinson treatment.	[154]