Pasireotide 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
Pasireotide
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 your medicines can affect the timing of your heartbeat. Amitriptyline (Elavil) and pasireotide (Signifor) can each stretch out a part of your heart's electrical cycle called the QT interval. When you take them together, that effect can add up, which in rare cases can lead to an irregular heartbeat.
This concern is based mostly on theory, not on lots of real-world reports, so please don't worry. The good news is your care team can manage this easily by checking a heart tracing (an ECG). Keep taking both medicines as prescribed and talk with your pharmacist or doctor about the best plan for you.
Effect: Additive QT-interval prolongation from coadministration of amitriptyline (a TCA with known QT effects) and pasireotide.
- Mechanism: Additive pharmacodynamic QT prolongation; both agents independently delay cardiac repolarization. Neither is a prodrug in this context.
- Direction/magnitude: Increased QTc; pasireotide prolonged QT at therapeutic and supratherapeutic doses in 2 studies. Combined magnitude not quantified.
- Evidence: Theoretical; severity rated major.
- Management: Baseline ECG and repeat ECG at 21 days after initiation. Monitor electrolytes (K+, Mg2+), correct as needed, and watch for concurrent QT-prolonging agents.
What happens
Increased risk of QT prolongation
Interaction Deep Dive
QT-interval prolongation is a known effect of pasireotide. Across 2 studies, this prolongation of the QT interval was seen with pasireotide given at therapeutic as well as supratherapeutic doses. When pasireotide is taken together with additional agents that prolong the QT interval, such as antiarrhythmic drugs, the QT-prolonging effects may be additive. For patients receiving pasireotide along with other QT-prolonging agents, obtaining ECGs at baseline and again 21 days after starting treatment is recommended1.
Why it happens (mechanism)
Additive QT-interval prolongation
How to manage this interaction
Your care team can keep this in check with monitoring rather than automatically stopping either drug.
- Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise.
- Your team may order an ECG (heart tracing) at the start and again about 21 days after starting the combination.
- They may also check blood levels like potassium and magnesium, since these affect heart rhythm.
- Report symptoms such as fainting, dizziness, palpitations, or an irregular heartbeat right away.
Ask your pharmacist or doctor if you have other medicines or conditions that affect your heart rhythm.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Pasireotide and Amitriptyline together?
Taking amitriptyline with pasireotide can add together to prolong the QT interval, so your care team will likely check an ECG at baseline and around day 21. Keep taking both as prescribed and report any fainting or palpitations. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Pasireotide 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 Pasireotide and Amitriptyline interaction managed?
Your care team can keep this in check with monitoring rather than automatically stopping either drug. Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise. Your team may order an ECG (heart tracing) at the start and again about 21 days after starting the combination. They may also check blood levels like potassium and magnesium, since these affect heart rhyth… 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 Pasireotide 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: SIGNIFOR(R) LAR intramuscular injection suspension, pasireotide intramuscular injection suspension. Novartis Pharmaceuticals Corporation (per FDA), East Hanover, NJ, 2014.
Keep reading about Amitriptyline
Keep reading about Pasireotide
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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