The Food and Drug Administration says a group of prostate drugs that can reduce the risk of some forms of prostate cancer may increase the risk of a more serious form of the disease.
The FDA says it is updating the warning information on a group of drugs including GlaxoSmithKline PLC's Avodart and Merck & Co.'s Proscar, which are used to shrink the prostate and which are linked to a greater risk of high-grade prostate cancers.
The agency is basing its conclusions on a review of two studies in which about 27,000 men 50 and older used the drugs for several years.
The FDA says the risk of high-grade prostate cancers is small, but doctors should be aware of it.
The drugs are also known as dutasteride and finasteride, respectively.