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Michael Okun Indu Subramanian Jonny Acheson

 

A neurologist weighs in on the top 5 questions and answers about Isradipine for Parkinson's disease: The data is out!

The Parkinson’s community has been waiting for the results of the blood pressure medication Isradipine for possible treatment of Parkinson’s disease. The National Institutes of Health funded a very large multi-center study and allocated millions of dollars into this effort. The study called STEADY-PD III was conducted in collaboration with the Parkinson’s Study Group and the MichaelJFox Foundation. We will review the top 5 questions and answers about Isradipine for Parkinson’s disease now that the data is out this week in the Annals of Internal Medicine!

What is Isradipine?

Dihydropyridine (Isradipine) is a calcium channel blocker most commonly used to treat high blood pressure. Many patients may know the drug from the name it is often marketed under (Dynacirc).

Why did a blood pressure medication become of interest for Parkinson’s disease? What is drug repurposing?

There have been studies in the literature which suggested the intriguing possibility that use of Isradipine could be associated with a reduced risk of the later development of Parkinson’s disease. 

Jim Surmeier is a leading scientist at Northwestern University, has studied the physiology of the brainstem in Parkinson’s disease. Jim discovered and described an effect in animals that suggested Isradipine may be a great drug target for treatment of Parkinson’s disease.

“Repurposing” a medication refers to the process of identifying candidate drugs which are already FDA approved for other purposes or diseases (e.g. in this case a drug for high blood pressure treatment or hypertension).

What was the study design for the large multi-center effort to study Isradipine and Parkinson’s disease?

The clinical trial was deigned and led by Tanya Simuni who is at the Northwestern Parkinson’s Foundation Center of Excellence and also by the NIH and PSG.

The study was designed to test Isradipine as a treatment to slow Parkinson’s disease progression.

The study design was published at clinicaltrials.org and also at Annals of Internal Medicine.

The investigation was a multicenter, randomized, parallel-group, double-blind, placebo-controlled trial and it included 57 Parkinson Study Group sites.  There was also listed collaboration from the MichaelJFox Foundation.

The study was limited to early-stage patients less than three years from their diagnosis.

Participants could not have previously been on dopamine drugs like Sinemet or an agonist.

The study was three years in duration. 

The active group received 5 mg of immediate-release Isradipine twice daily.

A placebo group was also used. 

Edema and dizziness were commonly reported as side effects from Isradipine.

What were the results of the clinical trial published in Annals of Neurology on March 30, 2020?

The authors suggested that maybe the Isradipine dose was too low and this contributed to the failure.

Do you recommend Isradipine for treatment of Parkinson’s disease in your patients?

There were several early animal and then human studies performed by the Northwestern Parkinson’s Foundation Center of Excellence. The animal studies were intriguing and the early human studies revealed that the drug was reasonably safe.

Isradipine did not slow the clinical disease progression in this group of early Parkinson’s disease patients.

Unfortunately based on the large multi-center study (NIH/NINDS and PSG study) we do not recommend the use of Isradipine either for symptomatic benefit or or slowing disease progression in Parkinson’s disease. There are also side effects from this drug which lowers blood pressure and could as Parkinson’s progresses lead to dizziness and passing out.

If you have been taking Isradipine outside of this study you should consult your doctor immediately to discuss whether you should potentially stop the drug.

See Dr. Okun’s summary of this trial at Neurology Journal Watch (NEJM) where he is also an associate editor.

To read more books and articles by Michael S. Okun MD check Twitter @MichaelOkun and these websites with blogs and information on his books and http://parkinsonsecrets.com/

#EndingPD #ParkinsonPACT #Parkinsonsecrets and https://www.tourettetreatment.com/

Michael Okun