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 Proscar
Both 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.