The US Food and Drug Administration (FDA) has alerted healthcare professionals about changes in the labeling for 5-alpha reductase inhibitors (5-ARI), which include Dutasteride and Finasteride.

 The drug labels now warn that there is an increased risk of being diagnosed with a high-grade prostate cancer while taking these drugs.

 Both drugs are marketed for use in benign prostate hypertrophy and have also been investigated for — but not approved for— prostate cancer prevention in men at high risk.  However, it was in these studies looking at prostate cancer prevention that there was a finding of an increased incidence of high-grade prostate cancer.

The FDA acknowledges that the risk appears to be low but says that practitioners need to be aware of this safety information. The known benefits can then be more accurately weighed against the potential risks when clinicians make a decision about starting or continuing treatment with 5-ARIs.