Itraconazole 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
Itraconazole
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 itraconazole (Sporanox) can each slightly slow the way your heart resets between beats, something doctors call QT prolongation. When you take them together, that effect can add up.
In rare cases, a very off-balance heart rhythm can happen, which is why your care team pays attention to this combo. The good news is that this concern is mostly theoretical, and your doctor and pharmacist can manage it easily. Keep taking both as prescribed, and let your team know if you feel fainting, dizziness, or a fluttering or pounding heartbeat.
Additive QT prolongation risk. Both amitriptyline and itraconazole independently prolong the QT interval. Concurrent use may produce additive delay in cardiac repolarization, increasing the theoretical risk of ventricular tachyarrhythmias including torsade de pointes.
- Mechanism: pharmacodynamic (additive QT effect), not a metabolic prodrug interaction.
- Direction: increased combined arrhythmogenic risk.
- Evidence: theoretical; severity: major; onset unspecified.
- Management: assess baseline ECG and QTc, correct electrolytes (K+, Mg2+), review other QT-prolonging agents, and monitor more closely. Dose selection should be individualized by the care team.
What happens
An increased risk of QT interval prolongation and torsade de pointes
Interaction Deep Dive
When itraconazole, an agent known to prolong the QT interval, is given together with another QT prolonging drug, the effects on QT can be additive, resulting in ventricular tachyarrhythmias, including instances of torsade de pointes, an arrhythmia that may be fatal12.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
This can be managed with monitoring and individualized dosing. Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise.
- Your care team may check an ECG (heart tracing) and your electrolyte levels, especially potassium and magnesium.
- They may monitor you more closely or adjust and individualize your doses.
- Tell them about any other medicines you take that affect heart rhythm.
- Contact your pharmacist or doctor promptly if you feel fainting, dizziness, palpitations, or an irregular heartbeat.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Itraconazole and Amitriptyline together?
Amitriptyline and itraconazole can both prolong the QT interval, so together they may add up and raise the risk of a dangerous heart rhythm; keep taking both as prescribed and ask your care team about heart and electrolyte monitoring. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Itraconazole 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 Itraconazole and Amitriptyline interaction managed?
This can be managed with monitoring and individualized dosing. Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise. Your care team may check an ECG (heart tracing) and your electrolyte levels, especially potassium and magnesium. They may monitor you more closely or adjust and individualize your doses. Tell them about any other medicines you take that affect… 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 Itraconazole 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 (2)
Keep reading about Amitriptyline
Keep reading about Itraconazole
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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