Alpha1-blocker therapy for lower urinary tract symptoms suggestive of benign prostatic obstruction: what are the relevant differences in randomised controlled trials?

Abstract

Randomised controlled trials (RCTs) provide the best available external evidence for the use of alpha1-blockers in treating lower urinary tract symptoms (LUTS) suggestive of benign prostatic obstruction (BPO). Placebo-controlled and actively-controlled RCTs evidenced the efficacy of alpha1-blockers in augmenting urine flow, relieving symptoms, reducing bother and improving quality of life in patients with LUTS. This improvement involves both filling (irritative) and voiding (obstructive) symptoms, occurs promptly and is well-maintained over time. Treatment benefit is independent of prostate size and baseline prostate specific antigen (PSA). There is no evidence of relevant differences between the different alpha1-blockers in this regard and all alpha1-blockers can be accepted as appropriately efficacious at the presently recommended doses. The best available external evidence for relevant differential properties of alpha1-blockers relates to their clinical selectivity in terms of the absence/presence of ancillary cardiovascular, i.e. anti-hypertensive effects. Anti-hypertensive alpha1-blockers (terazosin and doxazosin in particular) are more likely to cause dizziness and other cardiovascular untoward effects, eventually leading to premature treatment discontinuation. Alfuzosin (although primarily developed as an anti-hypertensive agent) and tamsulosin in contrast, are better tolerated; the former nevertheless carries a more distinct risk of symptomatic impairment of blood pressure control. Although indirect comparisons between different studies suggest a higher risk of retrograde ejaculation with tamsulosin, this hypothesis failed to be confirmed in direct comparative RCTs.