Lopinavir 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
Lopinavir
No brand names on record
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) is an older antidepressant, and lopinavir (part of an HIV combination) can also nudge the heart's electrical timing. When taken together, they may add up and stretch out a part of your heartbeat called the QT interval. In rare cases, that can lead to a dangerous irregular heartbeat.
This is a theoretical concern based on how each drug works, not something proven to happen often. Still, it's worth taking seriously. Please don't start, stop, or change either medicine on your own. Talk with your pharmacist or doctor, who can look at your full picture and keep you safe.
Effect: Additive QT-interval prolongation, increasing risk of serious ventricular arrhythmias (e.g., torsades de pointes).
Mechanism: Pharmacodynamic additive effect on cardiac repolarization. Amitriptyline (TCA) and lopinavir/ritonavir independently prolong QT. (Note: ritonavir is also a CYP3A4/CYP2D6 inhibitor and may raise amitriptyline exposure, compounding risk.)
Direction: Increased combined QT effect; neither drug is a prodrug here.
Evidence: Theoretical; severity rated major. Onset unspecified.
- Avoid concomitant use where possible.
- If unavoidable, obtain baseline/follow-up ECG, monitor QTc, correct K+/Mg2+, and review other QT-prolonging agents.
- Individualize therapy with the care team.
What happens
An increased risk of QT interval prolongation
Interaction Deep Dive
Concurrent administration of amitriptyline with lopinavir/ritonavir should be avoided, since the combination may produce additive QT interval prolongation and heighten the risk of serious cardiovascular effects1.
Why it happens (mechanism)
Additive effects on the QT interval
How to manage this interaction
The documented guidance is to avoid using these two together when possible because their effects on heart rhythm can add up.
- Keep taking both as prescribed unless your prescriber tells you otherwise, do not stop on your own.
- Ask your pharmacist or doctor whether one of these can be swapped for a safer alternative.
- If you must stay on both, your care team may monitor you more closely, including checking your heart tracing (ECG) and blood levels of potassium and magnesium.
- Report fainting, dizziness, palpitations, or a racing/irregular heartbeat right away.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Lopinavir and Amitriptyline together?
Amitriptyline and lopinavir can both prolong the QT interval, so combining them raises the risk of a dangerous heart rhythm; talk to your doctor or pharmacist about whether an alternative is possible or closer monitoring is needed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Lopinavir 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 Lopinavir and Amitriptyline interaction managed?
The documented guidance is to avoid using these two together when possible because their effects on heart rhythm can add up. Keep taking both as prescribed unless your prescriber tells you otherwise, do not stop on your own. Ask your pharmacist or doctor whether one of these can be swapped for a safer alternative. If you must stay on both, your care team may monitor you more closely, including che… 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 Lopinavir 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: KALETRA oral tablets, oral solution, lopinavir and ritonavir oral tablets, oral solution. Abbott Laboratories, North Chicago, IL, 2011. DailyMed
Keep reading about Amitriptyline
Keep reading about Lopinavir
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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