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. 1 Summary product characteristics (SPC) Propecia 2 Drugline no 14313 (year 1997) 3 Swedis (The Swedish Drug Information System) 4 Gelman CR, Rumack BH, Hess AJ (Eds): Drugdex(R) System; Micromedex, Inc., Englewood, Colorado (Edition expires (6/2001)) Finasteride 5 Finasteride In: Aronson JK, editor. Side effects of drugs. Annual 23. Amsterdam: Elsevier; 2000. p. 447-8. 6 Moore E, Bracken B, Brenmer W, Geller J, Imperato-McGinley J, McConnel J, Roy J, Tenover L, Vaughan D, Pappas F, Cook T, Gormely G, Stoner E. Proscar: five year experience. Eur Urol 1995; 28: 304-9 7 Stoner E. Three-year safety and efficacy data on the use of finasteride in the treatment of benign prostatic hyperplasia. Urology 1994; 43: 284-94 8 Wilton L, Pearce G, Edet E, Freemantle S, Stephens MDB, Mann RD. The safety of finasteride used in benign prostatic hypertrophy: a non-interventional observational cohort study in 14 772 patients. Br J Urol 1996; 78: 379-84 9 FASS 2001 (The Swedish catalogue of approved medical products) online 10 Micromedex Healthcare Series. Reprotox, System; Micromedex, Inc., Englewood, Colorado (Edition expires (6/2001)) Finasteride 11 Drugline no 17110 (year 2000) 12 Freidlin V, Ko HS, Wilkin JK. Re: chronic treatment with finasteride daily does not affect spermatogenesis or semen production in young men. J Urol 2000; 164: 1319-20