Amitriptyline and Donepezil: 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
Donepezil
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.
These two medicines can both affect your heart's rhythm. Amitriptyline (Elavil) is an older antidepressant, and donepezil (Aricept) is used for memory problems in dementia. Each one can slightly stretch out the time your heart takes to reset between beats. This is called QT prolongation. When you take them together, that effect can add up and, in rare cases, lead to a dangerous irregular heartbeat.
Please don't let this worry you too much. Your care team can manage this well by choosing the right doses and keeping an eye on your heart. Keep taking both as prescribed, and talk with your pharmacist or doctor if you feel faint, dizzy, or notice a racing or fluttering heartbeat.
Interaction: Additive QT-interval prolongation with increased risk of torsade de pointes when amitriptyline is combined with donepezil.
- Mechanism: Pharmacodynamic additive effect on cardiac repolarization; both agents independently prolong the QTc. No prodrug considerations apply.
- Direction/magnitude: Increased QTc; magnitude depends on dose, plasma levels, and patient risk factors.
- Onset: Delayed. Evidence: Probable. Severity: Major.
- Management: Use caution; obtain baseline and follow-up ECGs, correct electrolytes (K+, Mg2+), review other QT-prolonging agents, and individualize dosing. Monitor for syncope or palpitations.
What happens
Increased risk of QT-interval prolongation and torsade de pointes
Interaction Deep Dive
QT-interval prolongation has been reported in connection with donepezil12. Caution is warranted when donepezil is given together with other agents known to prolong the QT interval.
Why it happens (mechanism)
Additive QT-interval prolongation
How to manage this interaction
The good news is that your care team can manage this. Both drugs can affect heart rhythm, so your team may take steps to keep you safe:
- Keep taking both medicines exactly as prescribed unless your doctor tells you otherwise.
- Your team may check an ECG (heart tracing) and your blood levels of potassium and magnesium.
- Doses may need to be adjusted and individualized by your care team, and they may monitor you more closely.
- Tell your pharmacist about any other medicines you take, since some also affect heart rhythm.
Contact your doctor promptly if you feel faint, dizzy, or have a fluttering or pounding heartbeat.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Amitriptyline and Donepezil together?
Taking amitriptyline and donepezil together can add up to prolong your heart's QT interval, so your care team may check an ECG, correct electrolytes, and adjust doses. Keep taking both as prescribed and report any fainting or irregular heartbeat. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Amitriptyline and Donepezil interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How is the Amitriptyline and Donepezil interaction managed?
The good news is that your care team can manage this. Both drugs can affect heart rhythm, so your team may take steps to keep you safe: Keep taking both medicines exactly as prescribed unless your doctor tells you otherwise. Your team may check an ECG (heart tracing) and your blood levels of potassium and magnesium. Doses may need to be adjusted and individualized by your care team, and they may m… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
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 Donepezil 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 (2)
- Takaya T, Okamoto M, Yodoi K, et al: Torsades de Pointes with QT prolongation related to donepezil use. J Cardiol 2009; 54(3):507-511. PubMed
- Tanaka A, Koga S, & Hiramatsu Y: Donepezil-induced adverse side effects of cardiac rhythm: 2 cases report of atrioventricular block and Torsade de Pointes. Intern Med 2009; 48(14):1219-1223. PubMed
Keep reading about Amitriptyline
Keep reading about Donepezil
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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