Drug interactions
Phenylephrine + Pseudoephedrine
Severity: Moderate
Phenylephrine and Pseudoephedrine: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Both are sympathomimetic decongestants, so combining them duplicates therapy and increases the risk of hypertension, tachycardia, palpitations and tremor. Risk is greater in patients with cardiovascular disease.
What this interaction means in plain words
Phenylephrine and Pseudoephedrine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Phenylephrine belongs to Respiratory; Pseudoephedrine belongs to Respiratory.
Why it happens
Additive adrenergic agonist effects on vascular and cardiac receptors.
What to do
Avoid using two decongestants together, including combination cold products. Monitor blood pressure and heart rate if unavoidable.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Phenylephrine and Pseudoephedrine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Phenylephrine
- Isocarboxazid + Phenylephrine Contraindicated
- Phenelzine + Phenylephrine Contraindicated
- Phenylephrine + Tranylcypromine Contraindicated
- Bromocriptine + Phenylephrine Major
- Cocaine + Phenylephrine Major
- Dihydroergotamine intranasal + Phenylephrine Major
Other interactions of Pseudoephedrine
- Isocarboxazid + Pseudoephedrine Contraindicated
- Phenelzine + Pseudoephedrine Contraindicated
- Pseudoephedrine + Rasagiline Contraindicated
- Pseudoephedrine + Selegiline Contraindicated
- Pseudoephedrine + Selegiline transdermal Contraindicated
- Pseudoephedrine + Tranylcypromine Contraindicated
Frequently asked questions
Can I take Phenylephrine with Pseudoephedrine?
MediHelp rates the interaction as moderate. Phenylephrine and Pseudoephedrine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Both are sympathomimetic decongestants, so combining them duplicates therapy and increases the risk of hypertension, tachycardia, palpitations and tremor. Risk is greater in patients with cardiovascular disease.
How serious is the interaction between Phenylephrine and Pseudoephedrine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid using two decongestants together, including combination cold products. Monitor blood pressure and heart rate if unavoidable.
What other medicines interact with Phenylephrine?
MediHelp also lists interactions of Phenylephrine with, for example, Isocarboxazid, Phenelzine, Tranylcypromine. The full list is on the Phenylephrine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
