Men taking finasteride, a drug used to prevent prostate cancer, need not worry about sexual dysfunction side effects, according to a study from the Southwest Oncology Group.

Physicians usually warn patients that sexual dysfunction is a possible side effect when discussing finasteride.

This study came out of the Prostate Cancer Prevention Trial, a large National Cancer Institute-funded study which found that finasteride is effective at preventing prostate cancer in men age 55 and older. This trial showed that finasteride could reduce a man's risk of prostate cancer by almost 25 percent.

A popular baldness drug manufactured by Merck & Co Inc called Finasteride, better know as Propecia, can mask an important marker used to detect prostate cancer. High levels of the PSA in the blood can signal prostate cancer or other problems such as an enlarged prostate.

Propecia has been shown in a study to artificially lower the prostate specific antigen (PSA). Dr. Anthony D'Amico, the lead author of the study from Brigham and Women's Hospital in Boston, recommends middle-aged men taking Propecia to have their PSA levels multiplied by two to account for the difference. He says, "The main finding is that this drug called Propecia, which men use for hair loss typically between the ages of 30-60, affects the PSA levels".

Merck said in a statement that information has been included for customers on the label since the product was first introduced in 1997. It advises patients who undergo serum PSA tests to tell their doctor if they are taking Propecia.

It may be on the label but I hope our doctors are aware of this. Are they asking the patients if they are using Propecia? I'm sure there are plenty of men who have not read the fine print and don't mention this information to their physicians.