Pseudoephedrine mechanism of action?

Pseudoephedrine is a mixed-acting sympathomimetic decongestant.

- Indirect acting: it enters sympathetic nerve terminals and promotes release of norepinephrine (NE), and it also inhibits NE reuptake to some extent. This increases NE in the synapse.
- Direct acting: it has mild direct agonist activity at alpha-1 (and to a lesser extent beta) adrenergic receptors.

Net effect: alpha-adrenergic–mediated vasoconstriction of nasal mucosal vessels, reducing edema and nasal congestion. It can also cause mild CNS stimulation because it crosses the blood–brain barrier.

Notes: more effective for decongestion than phenylephrine due to the indirect NE release; can raise blood pressure and heart rate; has potential for misuse and is regulated in many places.