Source:http://linkedlifedata.com/resource/umls/id/C0304431
NCI: The sulfate salt form of pseudoephedrine, a phenethylamine and a diastereomer of ephedrine with sympathomimetic property. Pseudoephedrine sulfate displaces norepinephrine from storage vesicles in presynaptic neurones, thereby releasing norepinephrine into the neuronal synapses where it stimulates primarily alpha-adrenergic receptors. It also has weak direct agonist activity at alpha- and beta- adrenergic receptors. Receptor stimulation results in vasoconstriction and decreases nasal and sinus congestion.