FINASTERIDE - A REVIEW OF ITS POTENTIAL IN THE TREATMENT OF BENIGN PROSTATIC HYPERPLASIA

Finasteride is a novel therapeutic agent that selectively inhibits the enzyme 5alpha-reductase, thereby reducing prostatic dihydrotestostero ne (DHT) levels and prostate size. In men with symptomatic benign pros tatic hyperplasia (BPH), these effects have been associated with impro vements in peak urinary flow rate and urological symptoms, withdrawal from therapy, however, results in regrowth of the adenoma and long ter m therapy is therefore necessary. Although the magnitude of clinical i mprovement seen with finasteride has been perceived to be modest [espe cially when compared with that associated with transurethral resection of the prostate (TURP)], it has been maintained in the medium term (u p to 2 years) and thus may represent significant reversal of disease p rogression. Such beneficial effects, however, may not become apparent until completion of at least 6 months of therapy. Furthermore, since c linical studies have been unable to proactively identify a responsive subgroup, a trial period of 6 or possibly 12 months is necessary to as sess patient responsiveness. Despite these potential shortcomings, the benefits of therapy appear to outweigh the risks. Indeed finasteride is well tolerated; most adverse events have been related to sexual dys function (decreased libido, ejaculation disorders and impotence) and o ccurred in only a small proportion (about 2 to 3%) of patients. Moreov er, although there has been concern that finasteride might mask the de tection of prostate cancer through its decremental effects on serum pr ostate specific antigen (PSA) levels, careful monitoring in clinical t rials appears to have avoided this problem. Thorough pretreatment asse ssment and periodic follow-up examinations for malignancy are therefor e required in clinical practice. The role of finasteride in the treatm ent of patients with BPH is still emerging and will no doubt gain in c larity with further planned investigations. TURP (or other invasive pr ocedures such as the insertion of prostatic stents in patients unsuita ble for resection), continues to be the mainstay of therapy for those patients with severe symptomatic BPH. However, available data support a first line role for finasteride in the treatment of patients with un complicated symptomatic BPH. Within this setting, finasteride appears to offer a needed additional treatment option for those patients in wh om surgery is not indicated, and may be of special benefit to the cons iderable proportion of patients who opt not to undergo prostatectomy.