alpha(1)-blockers for BPH: Are there differences?

alpha(1)-blockers are well established for the treatment of lower urinary t ract symptoms (LUTS) suggestive of benign prostatic obstruction (BPO), prev iously referred to as benign prostatic hyperplasia (BPH). The various avail able alpha(1)-blockers do not differ in terms of their clinical efficacy, b ut there are several indications that alpha(1)-blockers differ qualitativel y with regard to their cardiovascular safety and tolerability, albeit the q uantification of these differences is subject to several constraints and pi tfalls. Clinical selectivity, i.e. the capacity of separating between desir ed urological and undesired (actually redundant) cardiovascular alpha(1)-bl ockade is not unlikely to relate to pharmacological selectivity (the relati ve preference to block the alpha(1A)- and alpha(1D)-adrenoceptor subtypes i n vitro, whilst hardly blocking alpha(1B)-adrenoceptors). On the other hand , both clinical and pharmacological selectivity are not unequivocally refle cted by experiments on so-called functional selectivity (in vivo experiment s that differentiate urological and cardiovascular effects). Generally, alp ha(1)-blockers that are efficacious in hypertension (doxazosin, terazosin, alfuzosin) are more likely to impair safety-relevant, physiological blood p ressure control in normotensives with LUTS than tamsulosin, which does not reduce elevated blood pressure in comparison with placebo and has little ef fect on orthostatic blood pressure control. However, clinical selectivity a nd cardiovascular safety are also defined by the treatment regimen (dose, d osage interval, formulation, step-up dose-increments for treatment initiati on, etc.) and by relevant patient-treatment interactions (co-morbidity and co-medication in particular). On the basis of the available information, ta msulosin administered once daily at a dose of 0.4 mg after breakfast (witho ut step-up increments) can be accepted as a highly convenient and efficacio us way to treat LUTS with a low cardiovascular safety risk, i.e. with a hig h level of clinically selectivity. Copyright (C) 1999 S. Karger AG, Basel.