Drug interactions
Doxepin + Phenylephrine
Severity: Moderate
Doxepin and Phenylephrine: 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
Tricyclic antidepressants can enhance the pressor response to direct-acting sympathomimetics by blocking norepinephrine reuptake. Hypertension and arrhythmias may occur, particularly with systemic phenylephrine.
What this interaction means in plain words
Doxepin and Phenylephrine 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.
Doxepin belongs to Dermatology; Phenylephrine belongs to Respiratory.
Why it happens
Inhibition of norepinephrine reuptake by doxepin potentiates adrenergic receptor stimulation.
What to do
Monitor blood pressure and heart rate, and use lower starting doses of phenylephrine. Prefer topical forms for decongestion.
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 Doxepin 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 Doxepin
- Doxepin + Isocarboxazid Contraindicated
- Doxepin + Phenelzine Contraindicated
- Doxepin + Procarbazine Contraindicated
- Doxepin + Safinamide Contraindicated
- Doxepin + Selegiline Contraindicated
- Doxepin + Tranylcypromine Contraindicated
Frequently asked questions
Can I take Doxepin with Phenylephrine?
MediHelp rates the interaction as moderate. Doxepin and Phenylephrine 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. Tricyclic antidepressants can enhance the pressor response to direct-acting sympathomimetics by blocking norepinephrine reuptake. Hypertension and arrhythmias may occur, particularly with systemic phenylephrine.
How serious is the interaction between Doxepin and Phenylephrine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood pressure and heart rate, and use lower starting doses of phenylephrine. Prefer topical forms for decongestion.
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.
