There is little need to worry about the long-term consequences of Proscar or Propecia (finasteride) use in men who use it to relieve symptoms of benign prostatic hyperplasia (BPH), for treatment of hair growth, or the prevention of cancer, new research shows.

The study, “Long-term Consequences of Finasteride vs Placebo in the Prostate Cancer Prevention Trial,” was published in the Journal of the National Cancer Institute.

Proscar is a widely prescribed medication for the treatment of BPH, and may improve the symptoms such as difficulty urinating, getting up during the night to urinate, hesitation at the start of urination, and decreased urinary flow. The medication is also used to treat male pattern hair loss (androgenetic alopecia).

Proscar has also been found to reduce the risk of prostate cancer. Long-term follow-up results from the Phase 3 study Prostate Cancer Prevention Trial (PCPT) have shown that regular use of Proscar decreases the risk of low-grade prostate cancer in men age 55 and older. These results were published in 2013 in the prestigious New England Journal of Medicine (NEJM).

Now, Joseph M. Unger, PhD, MS, and his colleagues at the SWOG Statistical Center at Fred Hutchinson Cancer Research Center linked Medicare claims records to assess the long-term adverse and beneficial effects of Proscar in 13,935 men who participated in the Prostate Cancer Prevention Trial (PCPT).

In the PCPT, men were randomly assigned to two treatment arms of either daily Proscar or a placebo. Patients were followed for seven years with an average Medicare follow-up evaluation time of 16 years from trial registration. The long-term effects examined were time to events, cardiac, endocrine, and sexual dysfunction, depression, diabetes, and BPH-related events.

“The most common adverse events observed in the finasteride arm … were sexual dysfunction and gynecomastia. In contrast, patients receiving finasteride had a lower incidence of urinary obstructive symptoms and complications because of benign prostatic hyperplasia,” the team wrote in the study, according to a news release. “Long-term consequences extending beyond the study period have not been well studied.”

The researchers found no differences between Proscar and the placebo treatment arms with respect to important baseline factors or the Medicare follow-up assessment time.

Men treated with Proscar had a 10 percent higher risk of new claims for depression and a 6 percent lower risk of procedures for BPH-related events (primarily lower urinary tract symptoms), the researchers found.

In addition, the results showed no other differences in rates of long-term consequences of intervention between patients treated with Proscar and those treated with a placebo.

Based on these findings, the researchers concluded that Proscar use is associated with a modest increase in depression but reduces the need for procedures to relieve BPH-related events.

“Few men take finasteride today for the prevention of prostate cancer, despite its availability as a low-cost generic drug. Our findings show that finasteride reduces long-term symptoms of benign prostatic hyperplasia with almost no adverse consequences,” Unger and his colleagues wrote.

“Therefore, there is little need to worry about long-term noncancer consequences of finasteride use in those who use it for treatment of symptomatic benign prostatic hyperplasia, hair growth, or prevention of cancer,” they wrote.