Dabrafenib and Amitriptyline: 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
Dabrafenib
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.
Both of these medicines can affect your heart's rhythm. Amitriptyline (Elavil) and dabrafenib (Tafinlar) can each slightly change the timing of your heartbeat, something doctors call QT prolongation. When you take them together, that effect can add up and, in rare cases, lead to an irregular heartbeat.
The good news is that this concern is mostly based on theory, not on a lot of real-world reports. Your care team can manage it well, often by checking your heart with an EKG and keeping an eye on things. Keep taking both as prescribed, and let your doctor or pharmacist know if you feel fainting, dizziness, or a racing or pounding heartbeat.
Effect: Additive QT-interval prolongation with concurrent amitriptyline and dabrafenib.
Mechanism: Pharmacodynamic (additive), not PK-based. Both agents independently prolong the QT interval; neither activation via a prodrug pathway is relevant here.
- Direction/magnitude: Increased QTc; magnitude not quantified.
- Onset: Unspecified.
- Evidence: Theoretical.
- Management: Obtain baseline and periodic ECG; monitor and correct electrolytes (K+, Mg2+); review other QT-prolonging agents. Watch for syncope, palpitations, or arrhythmia. Dose/therapy may be individualized by the care team.
What happens
An increased risk of QT interval prolongation
Interaction Deep Dive
When used on its own, dabrafenib carries the potential to lengthen the QT interval; as a result, its combined use with additional agents capable of prolonging the QT interval may produce additive effects on that interval1.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
This interaction is usually manageable with monitoring. Care teams that prescribe these together often take practical steps:
- Checking your heart rhythm with an EKG before and during treatment.
- Monitoring blood levels like potassium and magnesium, since low levels can worsen QT effects.
- Reviewing your other medicines for anything else that affects heart rhythm.
Keep taking both medicines exactly as prescribed unless your doctor tells you otherwise. If needed, your team may adjust and individualize your therapy or monitor you more closely. Tell your pharmacist or prescriber right away if you feel dizzy, faint, or have a fluttering or racing heartbeat.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Dabrafenib and Amitriptyline together?
Taking amitriptyline and dabrafenib together can add to the risk of an irregular heartbeat (QT prolongation), so keep both as prescribed and let your care team monitor your heart. Seek help if you feel faint, dizzy, or notice a racing heartbeat. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Dabrafenib and Amitriptyline 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 Dabrafenib and Amitriptyline interaction managed?
This interaction is usually manageable with monitoring. Care teams that prescribe these together often take practical steps: Checking your heart rhythm with an EKG before and during treatment. Monitoring blood levels like potassium and magnesium, since low levels can worsen QT effects. Reviewing your other medicines for anything else that affects heart rhythm. Keep taking both medicines exactly as… 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 Dabrafenib or Amitriptyline 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 (1)
- Product Information: TAFINLAR(R) oral capsules, tablets for suspension, dabrafenib oral capsules, tablets for suspension. Novartis Pharmaceuticals Corporation (per FDA), East Hanover, NJ, 2024. DailyMed
Keep reading about Amitriptyline
Keep reading about Dabrafenib
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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:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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