Health Canada

Health Canada

September 08, 2011 11:27 ET

GnRH Agonists: Heart-related Risk in Men Treated for Prostate Cancer

OTTAWA, ONTARIO--(Marketwire - Sept. 8, 2011) - Health Canada is informing health professionals and patients about a possible increased risk of certain heart-related events in men being treated for prostate cancer with a type of prescription drug known as a Gonadotropin-Releasing Hormone (GnRH) agonist.

There have been reports of heart attacks, stroke and heart-related deaths in patients treated with GnRH agonists for prostate cancer. Based on information collected from scientific literature, the risk appears to be low.

Patients taking a GnRH agonist drug should talk to their healthcare professional if they have a history of heart disease or heart disorders, or if they have any questions or concerns regarding their prostate cancer treatment. Before starting treatment with a GnRH agonist, tell your doctor if you have diabetes, heart disease, a previous heart attack or stroke, or any cardiovascular risk factors like high blood pressure, high cholesterol, or cigarette smoking. Patients should not stop taking a GnRH agonist drug without first talking to their health professional.

GnRH agonists work by reducing or suppressing male hormones (androgens, such as testosterone), which in turn leads to shrinkage of prostate tumours or slowing of the growth of prostate cancer. This therapy belongs to a category of therapies known as Androgen Deprivation Therapy. See below for a list of GnRH agonist drugs used in the treatment of prostate cancer in Canada.

When determining an appropriate prostate cancer treatment, physicians should weigh the benefits of Androgen Deprivation Therapy against the potential cardiovascular risk of GnRH agonists, along with any additional factors that may put a patient at increased risk for heart-related events. Patients receiving a GnRH agonist should be monitored for signs and symptoms suggestive of development of cardiovascular disease, and managed according to current clinical practice.

The labelling for GnRH agonist drugs has been updated to add a warning on the potential increased risk of heart-related side effects. Drug labels, or "Product Monographs," contain important prescribing and safety information for health professionals and patients, and are available by search of Health Canada's Drug Product Database (

How to report side effects to health products

To report suspected side effects to these or other health products, please contact Health Canada's Canada Vigilance Program toll-free at 1-866-234-2345, or complete a Canada Vigilance Reporting Form ( and send to us using one of these methods:

  • Fax: 1-866-678-6789
  • Internet:
  • Mail: Canada Vigilance Program
    Marketed Health Products Directorate
    Ottawa, ON, Address Locator 0701E
    K1A 0K9

GnRH agonist drugs currently marketed in Canada

GnRH agonist drugs used in the treatment of prostate cancer are available in injectable forms, as a nasal solution, and as a subdermal (under the skin) implant.

Brand Name Active Ingredient
Eligard leuprolide acetate
Lupron Depot (7.5 mg/syringe, 22.5 mg/syringe and 30.0 mg/syringe)
leuprolide acetate
Suprefact Depot
buserelin acetate
Trelstar triptorelin pamoate
Vantas histrelin acetate
Zoladex LA
goserelin acetate

Également disponible en français

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