On June 9, 2011, the U.S. Food and Drug Administration (FDA) informed the public of new safety information for drugs called 5-alpha reductase inhibitors (5-ARIs). Men who take these drugs may have an increased risk of being diagnosed with a more serious form of prostate cancer (high-grade prostate cancer). The Warnings and Precautions section of the labels for all FDA-approved 5-ARIs has been revised to include information about this risk.
Q1. What are 5-alpha reductase inhibitors (5-ARIs)?
A. 5-alpha reductase inhibitors (5-ARIs) are a class of prescription medicines primarily used to treat the symptoms of benign prostatic hyperplasia (BPH) in men. BPH is a common condition in men older than 40 and is characterized by an enlarged prostate and symptoms such as frequent urination and difficulty emptying the bladder. Drugs in this class are finasteride (marketed as Proscar [finasteride 5 mg] and Propecia [finasteride 1 mg]) and dutasteride (marketed as Avodart).
Avodart and Proscar are indicated for the treatment of BPH symptoms in men with an enlarged prostate. They are also approved to reduce the risk of urinary retention or surgery related to BPH.
Propecia is only indicated for the treatment of male pattern hair loss.
Q2. What is high-grade prostate cancer?
A. High-grade prostate cancer is an aggressive type of prostate cancer, meaning it grows and spreads faster compared to low-grade prostate cancer. High-grade prostate cancer is a serious disease, but accounts for a small portion of all diagnosed prostate cancers.
Q3. Why are the labels of all 5-ARIs being revised?
A. The labels of all 5-alpha reductase inhibitors (5-ARIs) are being revised based on FDA’s review of two large studies examining whether these drug products (Proscar, Avodart) reduce the risk of prostate cancer. The studies did find an overall reduction in the risk of lower-grade forms of prostate cancer, but both studies also showed an increased risk of high-grade prostate cancer.
As a result of these two studies, the labels of all FDA-approved 5-ARIs will be revised to include new information that these drug products may increase the risk of high-grade prostate cancer. The product labeling will also state that 5-ARIs are not approved for the prevention of prostate cancer.
