Proscar and Propecia, both versions of finasteride, will soon bear new label warnings regarding their association with long-term sexual side effects. According to the U.S. Food & Drug Administration (FDA), the Propecia and Proscar label changes will include:
- A revision to the Propecia label to include libido disorders, ejaculation disorders, and orgasm disorders that continued after discontinuation of the drug.
- A revision to the Proscar label to include decreased libido that continued after discontinuation of the drug.
- A revision to both the Propecia and Proscar labels to include a description of reports of male infertility and/or poor semen quality that normalized or improved after drug discontinuation.
Propecia and Proscar
Propecia (finasteride 1mg) and Proscar (finasteride 5 mg) are both part of a class of drugs known as 5-alpha reductase inhibitors, or 5-ARIs. Propecia is prescribed to treat male pattern baldness, while Proscar is prescribed to men with enlarged prostate. 5-ARIs like Propecia and Proscar work by preventing the conversion of androgen testosterone to DHT, a hormone critical to male sexual performance.
Propecia and Proscar Sexual Side Effects
Recently, a growing number of lawsuits have been filed around the country alleging Merck failed to warn Propecia and Proscar users about the serious side effects, including:
- erectile dysfunction
- low libido
- problems with orgasm
Last Spring, the Journal of Sexual Medicine published a study which found that at men using finasteride may develop an ongoing loss of libido and orgasm, even after they go off the medication. The study looked at 71 men who reported such side effects. The average duration of persistent sexual side effects was 40 months after they stopped taking finasteride. In about 20 percent of the cases, men reported suffering these side effects more than six years after stopping finasteride.
Merck changed the Propecia label in Sweden several years to warn that the drug could lead to permanent erectile dysfunction. Similar changes were made to the labels in the U.K. and Italy in 2009 and 2010. However, no changes were made to the U.S. label until last year, and even then it didn’t warn that sexual side effects could persist after men stopped taking Propecia.
FDA Propecia and Proscar Label Changes
According to the FDA, it has reviewed 421 postmarketing reports of sexual dysfunction among Propecia users between 1998 and 2011, 59 of which reported that the side effects lasted for at least three months after they stopped taking the drug. The agency also said it reviewed 131 cases of erectile dysfunction and 68 cases of lowered libido reported by users of Proscar.
In announcing the Proscar and Propecia label change, the FDA emphasized that clear causal links between finasteride (Propecia and Proscar) and sexual adverse events has NOT been established. However, the agency says the cases reported thus far suggest a broader range of adverse effects than previously reported in patients taking these drugs. The FDA also maintains that only a small number of men will experience sexual side effects from Propecia or Proscar, pointing out that its analysis of clinical trials showed 3.8 percent of men taking Propecia reported one or more of the sexual side effects, compared with 2.1 percent of those who received a placebo.