Atenolol and Tranylcypromine: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 15, 2026 · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Tranylcypromine
Atenolol
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
You've been prescribed tranylcypromine (Parnate), an older antidepressant, along with atenolol (Tenormin), a beta-blocker that slows the heart and lowers blood pressure. When taken together, they may add up and cause your heart to beat a bit too slowly or your blood pressure to drop when you stand up. That can leave you feeling dizzy, lightheaded, or faint.
I want to reassure you that this is a theoretical concern, meaning it hasn't been strongly proven, and your care team can manage it easily. Just watch for dizziness or a slow heartbeat, and let your pharmacist or doctor know so they can keep an eye on you.
Effect: Additive risk of more pronounced bradycardia and postural (orthostatic) hypotension when tranylcypromine (an MAOI) is combined with atenolol (a beta-1 selective blocker).
- Mechanism: Unknown; likely additive PD effects on cardiovascular tone. Neither agent's interaction here is driven by activation/inactivation of a prodrug.
- Direction: Increased cardiovascular depressant effect (bradycardia, BP drop on standing).
- Onset: Unspecified.
- Evidence: Theoretical.
- Management: Use with caution. Monitor heart rate, supine/standing BP, and symptoms of hypotension. Individualize dosing; consider closer follow-up when initiating or titrating.
What happens
An increased risk of more pronounced bradycardia and postural hypotension
Interaction Deep Dive
Use care when combining tranylcypromine with beta-blockers, since this pairing can heighten the likelihood of more marked bradycardia and postural hypotension1.
Why it happens (mechanism)
Unknown
How to manage this interaction
The good news is this interaction is manageable, and you should keep taking both medications exactly as prescribed unless your prescriber tells you otherwise.
Here is what typically happens and what you can do:
- Your care team may monitor your heart rate and blood pressure more closely, especially when either medication is started or the dose changes.
- Your dose may need to be adjusted and individualized by your team if symptoms appear.
- Stand up slowly to avoid lightheadedness.
- Tell your pharmacist or doctor if you notice dizziness, fainting, a very slow pulse, or feeling faint when you stand.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Atenolol and Tranylcypromine together?
Combining tranylcypromine with atenolol may add up to cause a slower heartbeat and dizziness when standing, but this is a theoretical concern your care team can manage with monitoring. Keep taking both as prescribed and report any dizziness or slow pulse. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Atenolol and Tranylcypromine interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Atenolol and Tranylcypromine interaction managed?
The good news is this interaction is manageable, and you should keep taking both medications exactly as prescribed unless your prescriber tells you otherwise. Here is what typically happens and what you can do: Your care team may monitor your heart rate and blood pressure more closely, especially when either medication is started or the dose changes. Your dose may need to be adjusted and individua… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Atenolol or Tranylcypromine need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (1)
- Product Information: Tranylcypromine oral tablets, tranylcypromine oral tablets. Solco Healthcare US, LLC (per DailyMed), Somerset, NJ, 2024. DailyMed
Keep reading about Tranylcypromine
Keep reading about Atenolol
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
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