The development of
finasteride (
PROSCAR, Merck & Co., Whitehouse Station, NJ) for the treatment of
benign prostatic hyperplasia (BPH) has had variable results. Numerous short-term and long-term studies comparing
finasteride with placebo have been reported. The results suggest that, physiologically, treatment with
finasteride significantly decreases levels of both serum and intraprostatic
dihydrotestosterone about 70% to 80% from baseline. In addition, total gland size decreases significantly-about 15% to 25% from baseline-particularly in the area of the periurethral zone of the prostate after
finasteride treatment. Baseline prostate size has been found to have a relation to efficacy of
finasteride treatment. The larger the prostate at baseline, the greater the urinary flow rate increase and symptom score decrease compared with placebo. Health-related quality-of-life parameters improved in those taking
finasteride. In studies evaluating combination
therapy, no significant differences were noted between those treated with an alpha blocker, such as
terazosin or
doxazosin in combination with
finasteride, and those receiving an alpha blocker alone. Long-term
finasteride versus placebo studies, such as the
PROSCAR Long-Term Efficacy and Safety Study (PLESS), suggest that long-term medical
therapy with
finasteride affects the natural history of the disease as manifested by the decrease in rates of acute
urinary retention and surgery. In patients who are "therapeutic responders," the degree of symptomatic improvement in those treated with
finasteride appears to be equal to that seen in patients receiving alpha blockers.
Prostate cancer detection rates did not differ between those treated with
finasteride and those receiving a placebo. The results of these studies suggest that physicians must evaluate what role
finasteride plays in the spectrum of available options for the treatment of BPH and
lower urinary tract symptoms. Baseline parameters, such as prostate volume,
prostate-specific antigen values, and whether to administer
finasteride in combination with alpha blockers, are among the factors that will determine the appropriateness of such
therapy.