Thursday, February 12, 2009

Isradipine Phase II Trials for Parkinson's Disease

Professor D. James Surmeier's exciting work investigating the relationship between calcium and sodium channel modulation and Parkinson's disease has been widely known in the Parkinson's community since his June 2007 article in Nature. The article described how isradipine restores older dopamine neurons to their youthful condition. In it Dr Surmeier describes how he feels that people may be able to take isradapine to protect brain cells from Parkinson's like they now take baby aspirin for their hearts. He also hopes that Isradipine can extend by two to three times the therapeutic window that patients have to continue taking L-DOPA before it loses its effectiveness or starts to have serious side effects.

A small clinical trial has been completed at Northwestern University proving the safely and tolerance of Isradipine in PD patients. The phase II trial, Safety and Tolerability of Isradipine (a potential neuroprotective agent) in Patients with Parkinson's Disease - Stage II is still in recruitment. (see: below)

With funding from the Michael J. Fox Foundation Dr Surmeier is now working with fellow Northwestern chemistry professor Dr Richard Silverman to develop a new drug (calcium channel blocker) that will just target one of the two calcium ion channels, Cav1.3 L-type calcium channel antagonist to slow or stop progression of the disease. Success could bring a patent and marketing by a major drug company.


Full text of clinical trial:


  1. my husband has PD and has been taking carbidopa/levodopa 100mg. x 3 a day since 2007.
    He was also taking Requip XL 6 mg. times 1 a day.
    He seems to get progressively worse since taking Regip. I call the doctor and she put him on ropinirole hcl 2 mg. 3 times a day and took him off the Requip. He is not to the point that he
    cannot walk without a walker. This has just happened in the last 4 wks. I am at my wits.

  2. We are so sorry to hear this. These unexplained changes can really turn things upside down.

    Requip XL 6mg, a dopamine agonist, is a stronger version of ropinerole. XL stands for extended release, meaning that it is released over time throughout the day. Sometime this kind of delayed release medication works better than others for the amount of medication released at one time.

    Ropinerole 2mg, is a generic version, which should save money. He is getting the same amount daily but in lower doses which are released at once.

    Perhaps the doctor felt that too much of the XL was releasing initially or that your husband needed more at one time - hard to say. Did she give you a reason for not upping the low levodopa/carbidopa dosage?

    What happened after he was put on Requip to make you feel that the issue was in the Requip.
    Is the walking issue due to muscle weakness? Postural Instability? Gait issues? Freezing?

    Does your husband have any urinary issues? How is his fluid intake? Is he getting less exercise because it is winter? Less sunlight?

    Are l-dopa/carbidopa and ropinerole his only medications? Diet? Nutritional supplements?

    We can't give you medical advice but we can share experience with you. Feel free to email Parkinson's Focus through Contact Us.


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