The use of alpha-adrenoceptor antagonists in lower urinary tract disease

alpha-adrenoceptor antagonists have traditionally been used in the treatment of hypertension but in recent years they have become increasingly common in the treatment of benign prostatic enlargement (BPE), where they reduce the 'dynamic' component of bladder outlet obstruction and appear to have additional actions to reduce irritative symptoms of the disease. Prazosin (Hypovase), Alza), doxazosin (Cardura), Pfizer), indoramin (Doralese), Wyeth-Ayerst Pharmaceuticals Inc.) and terazosin (Hytrin), Abbott Laboratories) are currently available in the UK for BPE but these agents have cardiovascular actions in a significant number of patients, inducing effects which must be considered adverse unless the patient also requires treatment for mild-to-moderate hypertension. The uroselective alpha-adrenoceptor antagonists tamsulosin (Flomax), Yamanouchi Pharmaceutical Co. Ltd.) and alfuzosin (Xatral), Sanofi-Synthelabo) have recently been introduced. These agents exert their selectivity via different mechanisms; selective tissue distribution for alfuzosin and alpha-adrenoceptor subtype selectivity for tamsulosin. The incidence of cardiovascular side effects for both drugs is similar to placebo. Several lines of evidence suggest that the alpha-adrenoceptor antagonists may relieve lower urinary tract (LUT) symptoms by other mechanisms additional to those which account for the reduction in bladder outlet obstruction. If correct, these agents may be of use in the treatment of other bladder conditions.