Amitriptyline and Propafenone: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Amitriptyline
Propafenone
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.
Amitriptyline (Elavil) and propafenone (Rythmol) can each affect the heart's electrical timing, something called the QT interval. When you take both, that effect can add up and, in theory, raise the risk of a dangerous irregular heartbeat.
The good news is that this concern is based on how these drugs work rather than on confirmed problems in people taking them together. Still, it's worth a conversation. Please keep taking both exactly as prescribed for now, and talk with your pharmacist or doctor so they can make sure this combination is right for you. Let them know right away if you feel fainting, palpitations, or a racing heart.
Effect: Additive QTc prolongation with increased risk of torsades de pointes and cardiac arrest.
Mechanism: Pharmacodynamic. Propafenone (Class Ic antiarrhythmic) and amitriptyline (TCA) each prolong the QTc; effects are additive. This is a PD interaction, not a metabolic/prodrug one, though note propafenone is a CYP2D6 substrate/inhibitor and amitriptyline is partly CYP2D6-dependent, which can further raise TCA levels.
- Direction: Increased combined cardiotoxic effect
- Onset: Unspecified
- Evidence: Theoretical; no formal interaction studies
- Management: Coadministration not recommended. If unavoidable, ECG/QTc and electrolyte monitoring, and individualized dosing by the care team.
What happens
An increased risk of cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest)
Interaction Deep Dive
At the doses recommended for therapy, Class I antiarrhythmics have demonstrated an ability to lengthen the QTc interval. Although no formal studies of drug interactions have been conducted, giving Class I antiarrhythmics together with other agents recognized to prolong the QTc interval, tricyclic antidepressants among them, is advised against345.
Why it happens (mechanism)
Additive effects on QT prolongation
How to manage this interaction
Because both drugs can stretch the heart's QT interval, guidance on file says using them together is not recommended. Your care team is best placed to decide.
- Do not stop or change either medicine on your own; keep taking both as prescribed until you've spoken with your prescriber.
- Ask your pharmacist or doctor whether an alternative to one of these drugs would be safer for you.
- If the combination is continued, your team may monitor you more closely (for example with heart tracings and blood tests) and may adjust and individualize your dose.
- Seek urgent care for fainting, palpitations, or a fast or irregular heartbeat.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) Electrocardiographic changes documented in patients taking therapeutic doses of tricyclic antidepressants include a faster heart rate, a lengthened PR interval, delays in intraventricular conduction, a lengthened corrected QT interval (QTc), and flattened T waves 1.
b) A 68-year-old man with agitated major depression was started on desipramine 125 mg daily, which yielded a subtherapeutic serum concentration of 442 nmol/L (therapeutic range = 500 to 1000 nmol/L). Raising the dose to 175 mg daily gave an excellent clinical response without adverse effects. He went on to develop atrial fibrillation and flutter. Digoxin 0.25 mg daily was added to his regimen, and desipramine was stopped. His arrhythmia was controlled by adding propafenone 150 mg twice daily plus 300 mg at bedtime. Desipramine 150 mg daily was restarted, at which time he experienced dry mouth, sedation, and shakiness; his desipramine serum level was found to be 2092 nmol/L. Desipramine was withheld for five days, the adverse effects resolved, and desipramine treatment was resumed at 75 mg daily. The desipramine serum level was then measured at 1130 nmol/L 2.
Common questions
Can I take Amitriptyline and Propafenone together?
Combining amitriptyline and propafenone can add up to a higher risk of dangerous heart rhythm problems, so this pairing is generally not recommended. Keep taking both as prescribed and ask your pharmacist or doctor promptly whether it should be changed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Amitriptyline and Propafenone interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Amitriptyline and Propafenone interaction managed?
Because both drugs can stretch the heart's QT interval, guidance on file says using them together is not recommended. Your care team is best placed to decide. Do not stop or change either medicine on your own; keep taking both as prescribed until you've spoken with your prescriber. Ask your pharmacist or doctor whether an alternative to one of these drugs would be safer for you. If the combination… 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.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Amitriptyline or Propafenone 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 a safer alternative to one of these medications for me?
References (5)
- Marshall JB & Forker AD: Cardiovascular effects of tricyclic antidepressant drugs: therapeutic usage, overdose, and management of complications. Am Heart J 1982; 103:401-414. PubMed
- Katz MR: Raised serum levels of desipramine with the antiarrhythmic propafenone (letter). J Clin Psychiatry 1991; 52:432-433.
- Product Information: Tambocor(R) flecainide acetate. 3M Pharmaceuticals, Northridge, CA, 1998.
- Larochelle P, Belanger L, Lemire F, et al: Dose-response effect of propafenone in patients with ventricular arrhythmias. Curr Ther Res 1984; 36:959-969. DOI
- Scagliotti D, Strasberg B, Hai HA, et al: Aprindine-induced polymorphous ventricular tachycardia. Am J Cardiol 1982; 49:1297-1300. PubMed
Keep reading about Amitriptyline
Keep reading about Propafenone
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