Current status of research on prostate‐selective α₁‐antagonists

Comparison of tamsulosin and naftopidil for efficacy and safety in the treatment of benign prostatic hyperplasia: a randomized controlled trial

“…Concerning the quantity of each of the α 1 subtypes in the human prostate, a recent study [13] showed that 69%, 3.3%, and 27% of the α 1 ‐ARs are subtypes of α 1a , α 1b and α 1d , respectively. In patients with BPH it was reported that α 1a subtypes increased to 85%, α 1d decreased to 14% and the amount of α 1b was negligible [14,15]. α 1 ‐AR antagonists that are not subtype selective were reported to be effective in relieving symptoms of BPH, but despite their clinical efficacy, the use of such α 1 ‐AR antagonists was associated with adverse effects secondary to vasodilatation and noradrenaline release, e.g.…”

Distribution of α1‐adrenoceptor subtype mRNAs in human renal cortex

“…How the subtypes operate in the human kidney is obscure. However, for patients with BPH, in which all subtypes are recognized and the α1a is predominant [10,11], nonselective α1‐blockers have been used effectively; recently tamsulosin (a relative blocker of α1a) was confirmed to be more effective for relaxing the prostate [23]. Furthermore, treatment with a nonselective α1‐blocker (doxazosin) was associated with significant rises in GFR in hypertensive patients with NIDDM [24].…”

Non‑Hormonal treatment of BPH/BOO

“…[11] In the neck of the human bladder, prostate, and urethra, it is the alpha-1a AR subtype that is most prevalent,[8] constituting two-thirds of alpha-1 receptors in normal prostates and up to 85% in prostates with BPH. [1213] AB work through antagonism of alpha-1a AR leading to relaxation of prostatic smooth muscle thereby counteracting the dynamic component of BOO caused by BPH. The non-subtype selective AB display similar affinity for all the alpha-1 AR subtypes and consequently cause vasodilation secondary to blockade of the alpha 1b-adrenoceptors that are most common in large blood vessels.…”