Pseudoephedrine
- Class: Decongestant
- Used for: nasal congestion
- Say it: soo-doh-eh-FED-rin
- Forms: tablet
PSEUDOEPHEDRINE is FALSE ephedrine — but the squeeze it puts on your vessels is not false at all.
The name is literal chemistry. Constricting vessels clears the nose, but the same constriction happens everywhere, which is why it can undo weeks of blood pressure treatment.
Pseudoephedrine is an alpha-1 agonist. Constricting the vessels in the nasal lining clears the blockage, but the same constriction happens in the rest of the circulation, which is why it raises blood pressure.
Side effects
Common: insomnia, nervousness, fast heartbeat
Serious: raised blood pressure
Typical dose
60 mg every 4–6 hours; maximum 240 mg daily
Check the blood pressure in anyone treated for hypertension.
Check yourself
Why should pseudoephedrine be used cautiously in treated hypertension?
- Its alpha-1 vasoconstriction is systemic, not confined to the nose
- It blocks the absorption of antihypertensive drugs
- It causes fluid retention through the kidney
- It is a direct beta-1 agonist on the heart
Show answer
A. Its alpha-1 vasoconstriction is systemic, not confined to the nose
The decongestant effect and the pressor effect are the same mechanism acting in two places. There is no way to constrict the nasal vessels selectively with a systemic dose, which is why the warning is intrinsic to the drug.
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