Mechanism of action Although originally thought to act as a direct agonist of adrenergic receptors,<unk>  was subsequently found to show only weak or negligible affinity for these receptors, and has been instead characterized as an indirect sympathomimetic which acts by inducing norepinephrine release and thereby activating adrenergic receptors. Pharmacodynamics<unk>  acts primarily as a selective norepinephrine releasing agent. It also acts as a dopamine releasing agent with around 10-fold lower potency. The stereoisomers of the drug have only weak or negligible affinity for α- and β-adrenergic receptors. Many sympathetic hormones and neurotransmitters are based on the phenethylamine skeleton, and function generally in "fight or flight" type responses, such as increasing heart rate, blood pressure, dilating the pupils, increased energy, drying of mucous membranes, increased sweating, and a significant number of additional effects. Activity profiles of isomers +<unk>  isomers, monoamine release (EC50, nM) Compound Norephedrine -Norephedrine 42.1 302 >10000 -Norephedrine<unk>  137 1371 >10000 Norpseudoephedrine -Norpseudoephedrine (cathine) 15.0 68.3 >10000 -Norpseudoephedrine 30.1 294 >10000 Pharmacokinetics Norephedrine is a metabolite of amphetamine, as shown below.
Phenylpropanolamine
Ergine
Cromoglicic acid
Tetrahydropapaveroline
Methylenedioxypyrovalerone
Azacyclonol
Papaverine
Cannabidiol