Drug interactions
Linezolid + Phenylephrine
Severity: Major
Linezolid and Phenylephrine: major 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
Linezolid is a reversible non-selective MAO inhibitor and can potentiate pressor amines. Systemic phenylephrine may cause a marked rise in blood pressure.
What this interaction means in plain words
Linezolid and Phenylephrine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Linezolid belongs to Anti Bacterial; Phenylephrine belongs to Respiratory.
Why it happens
MAO inhibition by linezolid increases the pressor response to phenylephrine.
What to do
Avoid oral decongestant doses. If a pressor is needed, start with a very low dose and titrate with close blood pressure monitoring.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Linezolid and Phenylephrine, 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 Linezolid
- Amoxapine + Linezolid Contraindicated
- Atomoxetine + Linezolid Contraindicated
- Benzphetamine + Linezolid Contraindicated
- Brimonidine + Linezolid Contraindicated
- Bupropion-naltrexone + Linezolid Contraindicated
- Bupropion + Linezolid Contraindicated
Frequently asked questions
Can I take Linezolid with Phenylephrine?
MediHelp rates the interaction as major. Linezolid and Phenylephrine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Linezolid is a reversible non-selective MAO inhibitor and can potentiate pressor amines. Systemic phenylephrine may cause a marked rise in blood pressure.
How serious is the interaction between Linezolid and Phenylephrine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid oral decongestant doses. If a pressor is needed, start with a very low dose and titrate with close blood pressure monitoring.
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.
