The hair-growth drug Propecia (finasteride) artificially lowers levels of prostate-specific antigen (PSA), a key indicator of prostate cancer, a new study has found. The study, appearing in The Lancet, calls for new clinical guidelines for doctors and urologists to be aware of the effects of the drug when evaluating PSA results.
"It's not universally known that finasteride lowers PSA levels in younger men who take it for hair growth," said study author Dr. Claus Roehrborn, of the University of Texas Southwestern Medical Center. "It is important for physicians to know that many young men take Propecia and that their PSA level is lowered artificially. Doctors need to adjust the PSA interpretation by multiplying it times-two for these men."
Finasteride was originally developed in the 1990s as a treatment for benign prostatic hyperplasia (BPH). In 1997 the FDA approved the drug for the treatment of male-pattern baldness. While the drug is administered at 1 milligram per day to treat baldness, patients who take it for BPH get a five times higher dosage. Researchers have known for some time that the testosterone metabolism process responsible for prostate growth also causes male-pattern baldness. It is this process that Finasteride blocks.
Dr. Roehrborn stressed that all doctors should be aware of the effect of hair-loss drugs on PSA results. "The impact of finasteride on PSA levels is significant. This needs to be realized by all internists, family-care doctors, dermatologists - anybody who writes prescriptions for male-pattern hair loss," he concluded.
Based on material from the University of Texas Southwestern Medical Center
