CARDIOVASCULAR EFFECTS OF ALPHA-BLOCKERS USED FOR THE TREATMENT OF SYMPTOMATIC BPH - IMPACT ON SAFETY AND WELL-BEING

Alpha-adrenoceptor antagonists (alpha-blockers) are efficacious in tre ating lower urinary tract symptoms (LUTS) suggestive of benign prostat ic obstruction (BPO), also termed symptomatic benign prostatic hyperpl asia (BPH), causing bladder outlet obstruction (BOO). There is little difference among the various a-blockers in terms of efficacy in treati ng LUTS. However, conventional quinazoline derivatives such as terazos in, doxazosin and alfuzosin, originally developed for hypertension, ha ve inherent cardiovascular extension effects, which influence the well being and safety of patients with LUTS by impairing physiological blo od pressure (BP) control, even when their effect on unchallenged BP ma y be quite low. Preclinically, tamsulosin, a sulphonamide-substituted phenethylamine, has a relative selectivity for the alpha(1)-adrenocept ors of the lower urinary tract. Clinically, this is associated with fe wer cardiovascular extension effects with tamsulosin (modified release capsule) 0.4 mg once daily. This allows the use of convenient regimen s of 0.4 mg tamsulosin administered once daily after breakfast from in itiation of treatment without the need for 'step-up' increases of dose to avoid 'first-dose' hypotension. Extensive investigation, including multiple orthostatic stress testing (which otherwise is unusual in th e characterization of alpha-blockers because of their inherent safety) , confirms that tamsulosin 0.4 mg definitely carries a lower risk of i mpaired BP control.