Finasteride had fewer sexual side effects compared to dutasteride in men with BPH

San Francisco-Although similarly effective for the relief of lower urinary tract symptoms, fewer sexual side effects were observed with finasteride (Proscar) compared to dutasteride (Avodart) in a retrospective study of men with BPH, Steven A. Kaplan, MD, reported at the AUA annual meeting.

As such, finasteride may be considered the "more optimal choice as primary therapy" for BPH, said Dr. Kaplan, professor of urology and chief of the Institute for Bladder and Prostate Health, Weill Cornell Medical College, New York.

The largest prospective study in which the two 5-alpha-reductase inhibitors (5-ARIs) were compared in men with BPH showed no differences in efficacy or safety between the two agents, but it remains unpublished.

Study fills research void

Furthermore, the pivotal phase III trials of dutasteride enrolled only men with prostate volumes of 30 grams or greater, whereas about half of the men with symptomatic BPH who were enrolled in MTOPS (Medical Therapy of Prostatic Symptoms), in which men could be randomized to finasteride, doxazosin (Cardura), the combination, or placebo, had prostate volumes less than 31 grams, Dr. Kaplan noted. If MTOPS is representative of the population of men with symptomatic BPH, then the performance of dutasteride has not been evaluated formally in a sizable proportion of men with this condition.

The analysis included 378 consecutive men (mean age, 58.7 years) from Weill Cornell Medical College who were treated with finasteride (197 patients) or dutasteride (211 patients). Of the men treated with finasteride, 57.4% remained on therapy at 5 years, compared to 42.5% treated with dutasteride.

At both 1 and 5 years, both drugs were associated with similar improvement in symptoms. At 5 years:

The improvements in symptoms from baseline were similar when analyzed by baseline prostate volume and PSA.

The level of PSA was reduced from baseline by about half with each treatment (48.9% with finasteride vs. 50% with dutasteride).

Fewer sexual side effects with finasteride

Sexual side effects resulted in more withdrawals from dutaseride therapy compared to finasteride. The percentage of men who withdrew from dutasteride due to erectile dysfunction was 5.1%, compared to 2.1% of men who withdrew from finasteride for the same reason. More men treated with dutasteride withdrew because of ejaculatory dysfunction and decreased libido (2.4% and 2.7%, respectively) compared to finasteride (1.8% and 1.4%, respectively).

Breast tenderness and/or enlargement was reported by three times as many men treated with dutasteride than with finasteride (3.5% vs. 1.2%).

"Both are good drugs; both are effective," Dr. Kaplan said.

"But because the sexual side effect profile appeared to be better with finasteride, it should be the 5-ARI of choice."