Medical therapy for benign prostatic hyperplasia: a review of the literature

To review the existing evidence regarding the efficacy and safety of medical therapy for lower urinary tract symptoms (LUTS) indicative of benign prostatic hyperplasia (BPH). To assess randomised controlled trials investigating the six alpha-adrenergic receptor antagonists (alpha-blockers), prazosin, alfuzosin, indoramin, terazosin, doxazosin, and tamsulosin, that benefit patients by relaxing prostatic smooth muscle, and the anti-androgen, finasteride, that mediates its more long-term benefits by reducing prostate size.

This review suggests that both classes of drug offer significant improvement in criteria used to evaluate symptomatic BPH and can be effective whilst being acceptably safe. Furthermore, the therapeutic efficacy of all contemporary alpha-blockers appear similar, both in terms of symptom relief and urodynamic improvements. Randomised controlled trials have additionally demonstrated that finasteride therapy can provide improvement in terms of quality of life indices, prostate volume, and risks of progressing to acute urinary retention or prostatic surgery. While alpha-blockers have a rapid onset of action, likely to produce a therapeutic result within weeks, regardless of whether prostatic enlargement or bladder outlet obstruction is present, finasteride appears to be effective for more long-term therapy for up to 4 years, but only in alleviating symptoms when they are associated with a significantly large prostate. Neither finasteride nor the alpha(1a)-receptor-selective blocker, tamsulosin, are associated with the lowering of blood pressure and incidence of cardiovascular side effects that are apparent with other less selective alpha-blocker therapies such as dizziness and postural hypertension. They are, however, both associated with an increased risk of sexual dysfunction, albeit less than those associated with surgical intervention. Whereas tamsulosin is associated only with ejaculatory dysfunction, finasteride is additionally linked to decreased libido and impotence.