Drug interactions
Diphenoxylate-atropine + Phenylephrine
Severity: Minor
Diphenoxylate-atropine and Phenylephrine: minor 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
Phenylephrine is an alpha-adrenergic agonist that raises blood pressure, and atropine can cause tachycardia. Combined systemic use may produce a greater pressor response with a rise in heart rate, but the effect is usually minor at normal doses.
What this interaction means in plain words
Diphenoxylate-atropine and Phenylephrine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Diphenoxylate-atropine belongs to Gastrointestinal Tract; Phenylephrine belongs to Respiratory.
Why it happens
Phenylephrine's pressor effect is combined with the vagolytic tachycardia caused by atropine.
What to do
No routine action is needed. Monitor blood pressure and heart rate in patients with cardiovascular disease.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Diphenoxylate-atropine 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 Diphenoxylate-atropine
- Diphenoxylate-atropine + Isocarboxazid Contraindicated
- Diphenoxylate-atropine + Phenelzine Contraindicated
- Diphenoxylate-atropine + Tranylcypromine Contraindicated
- Alfentanil + Diphenoxylate-atropine Major
- Alvimopan + Diphenoxylate-atropine Major
- Amitriptyline + Diphenoxylate-atropine Major
Other interactions of Phenylephrine
- Isocarboxazid + Phenylephrine Contraindicated
- Phenelzine + Phenylephrine Contraindicated
- Phenylephrine + Tranylcypromine Contraindicated
- Bromocriptine + Phenylephrine Major
- Cocaine + Phenylephrine Major
- Dihydroergotamine intranasal + Phenylephrine Major
Frequently asked questions
Can I take Diphenoxylate-atropine with Phenylephrine?
MediHelp rates the interaction as minor. Diphenoxylate-atropine and Phenylephrine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Phenylephrine is an alpha-adrenergic agonist that raises blood pressure, and atropine can cause tachycardia. Combined systemic use may produce a greater pressor response with a rise in heart rate, but the effect is usually minor at normal doses.
How serious is the interaction between Diphenoxylate-atropine and Phenylephrine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine action is needed. Monitor blood pressure and heart rate in patients with cardiovascular disease.
What other medicines interact with Diphenoxylate-atropine?
MediHelp also lists interactions of Diphenoxylate-atropine with, for example, Isocarboxazid, Phenelzine, Tranylcypromine. The full list is on the Diphenoxylate-atropine 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.
