Drug interactions
Diphenoxylate-atropine + Selegiline
Severity: Major
Diphenoxylate-atropine and Selegiline: major interaction.
Last updated Sources: UK SmPC
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
Diphenoxylate is an opioid structurally related to meperidine, and combining it with an MAO inhibitor has been associated with hypertensive crisis or severe CNS effects. Selegiline is selective for MAO-B at low oral doses but loses selectivity at higher doses, so the risk is dose dependent.
What this interaction means in plain words
Diphenoxylate-atropine and Selegiline 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.
Diphenoxylate-atropine belongs to Gastrointestinal Tract; Selegiline belongs to Central Nervous System.
Why it happens
Possible serotonergic or catecholaminergic potentiation through MAO inhibition; the exact mechanism is not well established.
What to do
Avoid the combination where possible and choose another antidiarrheal such as loperamide. If used, keep selegiline at the lowest MAO-B-selective dose and monitor blood pressure, temperature and sedation.
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?
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References
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 Selegiline
- Amitriptyline + Selegiline Contraindicated
- Amoxapine + Selegiline Contraindicated
- Atomoxetine + Selegiline Contraindicated
- Benzphetamine + Selegiline Contraindicated
- Brimonidine + Selegiline Contraindicated
- Buprenorphine long-acting + Selegiline Contraindicated
Frequently asked questions
Can I take Diphenoxylate-atropine with Selegiline?
MediHelp rates the interaction as major. Diphenoxylate-atropine and Selegiline 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. Diphenoxylate is an opioid structurally related to meperidine, and combining it with an MAO inhibitor has been associated with hypertensive crisis or severe CNS effects. Selegiline is selective for MAO-B at low oral doses but loses selectivity at higher doses, so the risk is dose dependent.
How serious is the interaction between Diphenoxylate-atropine and Selegiline?
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 the combination where possible and choose another antidiarrheal such as loperamide. If used, keep selegiline at the lowest MAO-B-selective dose and monitor blood pressure, temperature and sedation.
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.
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