Selective alpha 1-adrenoceptor antagonists in benign prostatic hyperplasia: rationale and clinical experience

Symptomatic benign prostatic hyperplasia (BPH) is a common condition in older men and has a significant impact on their daily lives. Transurethral resection of the prostate is currently the most effective remedy for BPH but is not suitable for all patients. There is now clear evidence for the efficacy of alpha-adrenoceptor antagonists, particularly selective alpha 1-adrenoceptor antagonists, in the treatment of BPH. Inhibition of alpha-adrenoceptors significantly increases urinary flow and improves symptoms in BPH. alpha 1-Adrenoceptor antagonists have a place in the management of BPH patients with mild to moderate disease, who are bothered by their symptoms, or for those awaiting or wishing to delay surgery. Treatment with selective alpha 1-adrenoceptor antagonists is generally better tolerated than nonselective-alpha-blockers. alpha 1-Selective adrenoceptor antagonists with a long half-life such as terazosin, doxazosin and tamsulosin, as a modified release formulation, permit once-daily dosing. Tamsulosin is the first subtype-specific (cloned alpha 1c/functional alpha 1A) adrenoceptor antagonist in clinical practice. Initial reports suggest that it gives no clinically relevant lowering of blood pressure and that its (vasodilatory) side effect profile is minimal. The scientific rationale behind the therapeutic use of alpha-adrenergic blockade as treatment for BPH and the trials data relating to the various agents which are available for clinical use are reviewed in the context of the contemporary literature.