Propecia, a drug for treating baldness, and Proscar for treating enlarged prostate, are to carry labels warning about sexual adverse events, including decreased libido, ejaculation problems, and difficulties with orgasm. According to the FDA, in some cases these problems can continue well after the patient stops taking the medication.
Proscar (finasteride 5 mg) will have a label warning about reduced libido, while Propecia's (finasteride 1 mg) label will mention libido, orgasm and ejaculation disorders (after treatment is over). Both medications will also have warnings about poor semen quality and infertility risk - both these adverse events soon resolve after treatment is over.
In an online statement, the FDA wrote:
"Despite the fact that clear causal links between finasteride (Propecia and Proscar) and sexual adverse events have not been established, the cases suggest a broader range of adverse effects than previously reported in patients taking these drugs."
The FDA stresses that clear casual links between Propecia/Proscar and sexual side effects have not been compellingly established. However, according to studies the Agency has examined, there is a broader range of sexual adverse effects than previously reported among patients taking these medications.
Details on these possible side effects should be explained to patients, the FDA adds. Both prescribers and patients should be aware of them when discussing the risks and benefits of finasteride.
421 reports of sexual dysfunction related to Propecia that occurred from 1998 to 2011 were reviewed by the FDA. In fifty-nine of these cases, the problems continued for longer than three months after the patients stopped taking their medication. There were 131 cases of erectile dysfunction and 68 of reduced sex drive (libido) related to Proscar (1992-2010).
Propecia and ProscarBoth drugs contain finasteride, the active ingredient. Finasteride is a 5 alpha-reductase inhibitor.
Proscar (finasteride 5 mg) was FDA approved in 1992 for treating the symptoms related to enlarged prostate (benign prostatic hyperplasia). It is also approved for treating urinary retention (reducing risk), or the need for surgery related to benign prostatic hyperplasia. Propecia (finasteride 1 mg) was approved in 1997 by the FDA. It is used only by men for treating male pattern hair loss.
Finasteride is made and sold by Merck. Pamela Eisele, a spokesperson for the company, said:
"Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Merck believes that Propecia and Proscar are generally well tolerated and effective for their respective indicated use when used in accordance with their approved labeling."
The FDA emphasized:
"Only a small percentage of men using these drugs have experienced a
sexual adverse event."
Written by Christian Nordqvist