How long can you expect erectile dysfunction, as an adverse effect of finasteride (Propecia) treatm

Fråga: How long can you expect erectile dysfunction, as an adverse effect of finasteride (Propecia) treatment, to remain and can it affect male fertility? A 23-year-old male treated with finasteride (Propecia) for alopecia developed erectile dysfunction with reduced ejaculate, reduced erection and absence of morning erection. He has been treated with finasteride 1.0 mg daily for two years but stopped treatment five months ago. The side effects have still not subsided.

Sammanfattning: Finasteride treatment is known to cause untoward sexual dysfunction. However, there are no convincing reports on irreversible long-term sexual adverse effects after discontinuing the finasteride treatment. It is not likely that finasteride will affect spermatogenesis or fertility.

Svar: Finasterid is an orally active 5-alpha-reductase inhibitor used for prostatic hyperplasia and alopecia. The enzyme 5-alpha-reductase catalyses the conversion of testosterone to dihydrotestosterone (DHT) (1,2). The most common adverse effect reported for finasteride treatment is sexual dysfunction (2-5). The frequency of impotence reported is around four per cent, decreased libido around three per cent and reduced semen volume is up to 25 percent in patients with doses up to 5 mg (2,5).

There are no reported cases of long-term sexual dysfunctions associated with finasteride

0-10 mg treatments in the literature (1,5-8). All reported adverse effects have been reversible and disappeared after discontinuing the drug. However, in follow up studies several patients dropped out of the studies due to sexual adverse effects. This makes it difficult to evaluate whether the adverse effects were irreversible or not.

Six cases of sexual dysfunction (two impotence, three reduced libidos and one swollen testicle) following finasteride treatment have been reported to the Swedish Adverse Drug Reactions Advisory Committee (SADRAC) (3). All patients had been treated with 5 mg finasteride. In one of the reports, the patient had persistent impotence problems six months after discontinuing finasteride treatment. This case must be evaluated on the basis of the patients age (79 years) and that he suffers from prostatic hyperplasia (3).

Finasteride has a half-life of 3-14 hours (average 6 hours) and is therefore expected to be eliminated from the body at this time (9).

Minute amount of finasteride has been detected in the semen and is not likely to affect the spermatogenesis and therefore influence fertility or give rise to malformations (1,10-12).

We recommend that the present case be reported to SADRAC.