The effect of finasteride in men with benign prostatic hyperplasia. The Finasteride Study Group.
BACKGROUND
Benign prostatic hyperplasia is a progressive, androgen-dependent disease resulting in enlargement of the prostate gland and urinary obstruction. Preventing the conversion of testosterone to its tissue-active form, dihydrotestosterone, by inhibiting the enzyme 5 alpha-reductase could decrease the action of androgens in their target tissues; in the prostate the result might be a decrease in prostatic hyperplasia and therefore in symptoms of urinary obstruction.


METHODS
In a double-blind study, we evaluated the effect of two doses of finasteride (1 mg and 5 mg) and placebo, each given once daily for 12 months, in 895 men with prostatic hyperplasia. Urinary symptoms, urinary flow, prostatic volume, and serum concentrations of dihydrotestosterone and prostate-specific antigen were determined periodically during the treatment period.


RESULTS
As compared with the men in the placebo group, the men treated with 5 mg of finasteride per day had a significant decrease in total urinary-symptom scores (P less than 0.001), an increase of 1.6 ml per second (22 percent, P less than 0.001) in the maximal urinary-flow rate, and a 19 percent decrease in prostatic volume (P less than 0.001). The men treated with 1 mg of finasteride per day did not have a significant decrease in total urinary-symptom scores, but had an increase of 1.4 ml per second (23 percent) in the maximal urinary-flow rate, and an 18 percent decrease in prostatic volume. The men given placebo had no changes in total urinary-symptom scores, an increase of 0.2 ml per second (8 percent) in the maximal urinary-flow rate, and a 3 percent decrease in prostatic volume. The frequency of adverse effects in the three groups was similar, except for a higher incidence of decreased libido, impotence, and ejaculatory disorders in the finasteride-treated groups.


CONCLUSIONS
The treatment of benign prostatic hyperplasia with 5 mg of finasteride per day results in a significant decrease in symptoms of obstruction, an increase in urinary flow, and a decrease in prostatic volume, but at a slightly increased risk of sexual dysfunction.
Gormley
G J
GJ
Merck Research Laboratories, Rahway, NJ 07065.
Stoner
E
E
Bruskewitz
R C
RC
Imperato-McGinley
J
J
Walsh
P C
PC
McConnell
J D
JD
Andriole
G L
GL
Geller
J
J
Bracken
B R
BR
Tenover
J S
JS
D058891:5-alpha Reductase Inhibitors; D000328:Adult; D000368:Aged; D000736:Androstenes / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001378:Azasteroids / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D013196:Dihydrotestosterone / Q000097:blood; D004311:Double-Blind Method; D007172:Erectile Dysfunction / Q000209:etiology; D018120:Finasteride; D006801:Humans; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000473:pathology; D017430:Prostate-Specific Antigen / Q000032:analysis; D011470:Prostatic Hyperplasia / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D014563:Urodynamics
D058891:5-alpha Reductase Inhibitors; D000736:Androstenes; D001378:Azasteroids; D013196:Dihydrotestosterone; D018120:Finasteride; D017430:Prostate-Specific Antigen