Voriconazole 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
Voriconazole
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 voriconazole (Vfend) can each affect the heart's electrical rhythm in a small way. When you take them together, those effects can add up and cause something called QT prolongation, which in rare cases can lead to a serious irregular heartbeat.
The good news is this concern is based mostly on how the drugs work rather than lots of real-world problems, and your care team can manage it. Please keep taking both medicines as prescribed, and let your pharmacist or doctor know if you feel dizzy, faint, or notice a pounding or racing heartbeat. They may keep a closer eye on your heart to keep you safe.
Interaction: Additive QT interval prolongation when amitriptyline is combined with voriconazole. Both agents independently prolong the QT interval, so co-administration increases the risk of QTc prolongation and, rarely, torsades de pointes.
- Mechanism: Pharmacodynamic (additive) QT effect; not a primary CYP-mediated PK interaction here.
- Direction: Increased combined QT-prolonging effect.
- Evidence: Theoretical; severity graded major.
- Onset: Unspecified.
- Management: Assess baseline/on-treatment ECG, correct electrolytes (K+, Mg2+), review other QT-prolonging drugs, and monitor for arrhythmia. Dose individualized by the care team.
What happens
An increased risk of QT interval prolongation
Interaction Deep Dive
Because concurrent administration of voriconazole with agents that prolong the QT interval may produce additive effects on the QT interval and heighten the risk of serious cardiovascular effects, caution is advised when these drugs are used together1.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
Your care team can manage this combination safely. Here is what they typically do and what you can do:
- Monitoring: Your team may check an ECG and blood levels of potassium and magnesium, and watch you more closely.
- Dose: Doses may need to be adjusted and individualized by your care team.
- Your part: Keep taking both exactly as prescribed unless your prescriber tells you otherwise.
- Speak up: Tell your pharmacist or doctor about any fainting, dizziness, or an irregular or racing heartbeat, and share a full list of your other medicines.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Voriconazole and Amitriptyline together?
Amitriptyline and voriconazole can both prolong the QT interval, so together they may raise the risk of a serious heart rhythm problem. Keep taking both as prescribed and ask your care team about heart monitoring. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Voriconazole 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 Voriconazole and Amitriptyline interaction managed?
Your care team can manage this combination safely. Here is what they typically do and what you can do: Monitoring: Your team may check an ECG and blood levels of potassium and magnesium, and watch you more closely. Dose: Doses may need to be adjusted and individualized by your care team. Your part: Keep taking both exactly as prescribed unless your prescriber tells you otherwise. Speak up: Tell yo… 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 Voriconazole 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: VFEND(R) oral tablets, oral suspension, intravenous injection, voriconazole oral tablets, oral suspension, intravenous injection. Roerig (per FDA), New York, NY, 2025. DailyMed
Keep reading about Amitriptyline
Keep reading about Voriconazole
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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