cirazoline

Cirazoline (free base) is a full agonist at the α1A adrenergic receptor, a partial agonist at both the α1B and α1D adrenergic receptors, and a nonselective antagonist to the α₂ adrenergic receptor. It is believed that this combination of properties could make cirazoline an effective vasoconstricting agent.

Cirazoline hydrochloride is a competitive full agonist of the α1A-adrenergic receptor (α1A-AR; Ki: 120 nM). It is a partial agonist at α1B-AR (Ki: 960 nM) and α1D-AR (Ki: 660 nM).

The alpha-adrenoceptors blocking effect of (N-piperidinomethyl)-2-chromanne was studied in vivo and in vitro in the rat. In the pithed rat, (N-piperidinomethyl)-2-chromanne (1 mg kg i.v.) antagonized the pressor effects induced by alpha agonists. (N-piperidinomethyl)-2-chromanne competitively antagonized the pressor effects of M7 (alpha 2-agonist) and cirazoline (alpha 1-agonist). (N-piperidinomethyl)-2-chromanne antagonized the inhibitory effects of clonidine on presynaptic alpha 2-receptors in stimulated pithed rats.