(-)-Norephedrine
Phenylpropanolamine is an alpha- and beta-adrenergic receptor agonist with sympathomimetic activity. Phenylpropanolamine (PPA) binds to and activates alpha- and beta-adrenergic receptors in the mucosa of the respiratory tract resulting in vasoconstriction and reduction in swelling of nasal mucous membranes and reduction in tissue hyperemia, edema, and nasal congestion. This agent also stimulates the release of norepinephrine from its storage sites resulting in the effects already described. Finally, PPA indirectly stimulates beta-receptors producing tachycardia and a positive inotropic effect.