Pharmacodynamics<unk>  is an α1-blocker that acts as a non-selective inverse agonist at α1-adrenergic receptors, including of the α1A-, α1B-, and α1D-adrenergic receptor subtypes. It binds to these receptors with affinity (Ki) values of 0.13 to 1.0 nM for the α1Α-adrenergic receptor, 0.06 to 0.62 nM for the α1B-adrenergic receptor, and 0.06 to 0.38 nM for the α1D-adrenergic receptor. It has much lower affinity for the α2-adrenergic receptors (Ki = 210–5,012 nM for the α2A-adrenergic receptor, 13–398 nM for the α2B-adrenergic receptor, and 10–200 nM for the α2C-adrenergic receptor). The α1-adrenergic receptors are found in vascular smooth muscle, where they are responsible for the vasoconstrictive action of norepinephrine. They are also found throughout the central nervous system. α1-Adrenergic receptors have additionally been found on immune cells, where catecholamine binding can stimulate and enhance cytokine production. Pharmacokinetics<unk>  has an onset of action of 30 to 90 minutes, the elimination half-life of<unk>  is 2 to 3 hours, and its duration of action is 10 to 24 hours.
Prazosin
Phenylephrine
Acebutolol
Terazosin
Doxazosin
Tamsulosin
Silodosin
Hydrastine