Amitriptyline and Haloperidol: 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
Haloperidol
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 amitriptyline (Elavil) and haloperidol can affect your heart's electrical rhythm. Each one can slightly stretch out a part of your heartbeat called the QT interval. When you take them together, those effects can add up, which in rare cases could lead to a dangerous irregular heartbeat.
I want to be honest with you: this concern is based on how these drugs work, not on studies proving it happens often. Still, it is taken seriously. The good news is your care team can manage this. Please don't stop either medication on your own. Just talk with your doctor or pharmacist so they can decide the safest plan for you.
Effect: Additive risk of QT-interval prolongation, torsades de pointes, and cardiac arrest when a TCA (amitriptyline) is combined with an antipsychotic (haloperidol).
- Mechanism: Additive cardiac repolarization delay; both agents independently prolong the QT interval.
- Direction: Additive PD effect (neither is a prodrug in a way that alters this).
- Evidence: Theoretical; no formal interaction studies. Onset unspecified.
- Management: Coadministration generally not recommended. If unavoidable, obtain baseline and follow-up ECGs, correct electrolytes (K+, Mg2+), review other QT-prolonging agents, and use the lowest effective doses with close monitoring.
What happens
An increased risk of cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest)
Interaction Deep Dive
A number of antipsychotic medications carry a risk of QT-interval prolongation23456. While no formal studies of drug interactions have been conducted, it is advised against giving a tricyclic antidepressant together with an antipsychotic7.
Why it happens (mechanism)
Additive cardiac effects
How to manage this interaction
Your care team has a few ways to handle this combination safely:
- Keep taking both exactly as prescribed unless your doctor tells you otherwise. Do not stop either one on your own.
- Your team may check your heart rhythm with an ECG and review your electrolyte levels (like potassium and magnesium).
- Doses may need to be adjusted and individualized, and your team may monitor you more closely.
- They may also consider whether a different medication is a better fit for you.
Tell your doctor or pharmacist if you feel a fast or irregular heartbeat, dizziness, or fainting.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) Cardiac electrical alterations observed during clinical trials of pimozide have included lengthening of the corrected QT interval, flattening, notching, and inversion of the T wave, and the emergence of U waves. In experimental investigations, sudden and unexpected deaths have been reported in patients receiving pimozide at doses of 1 mg/kg. The suggested mechanism for these fatalities is QT interval prolongation, which predisposes patients to ventricular arrhythmias 1.
Common questions
Can I take Amitriptyline and Haloperidol together?
Combining amitriptyline and haloperidol can add to the risk of a dangerous heart rhythm problem, so this pairing is generally avoided. Don't change anything yourself, but talk with your doctor or pharmacist about the safest option. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Amitriptyline and Haloperidol 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 Amitriptyline and Haloperidol interaction managed?
Your care team has a few ways to handle this combination safely: Keep taking both exactly as prescribed unless your doctor tells you otherwise. Do not stop either one on your own. Your team may check your heart rhythm with an ECG and review your electrolyte levels (like potassium and magnesium). Doses may need to be adjusted and individualized, and your team may monitor you more closely. They may… 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 Amitriptyline or Haloperidol 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 (7)
- Product Information: Orap(R), pimozide. Gate Pharmaceuticals, Sellersville, PA, 1999. DailyMed
- O'Brien JM, Rockwood RP, & Suh KI: Haloperidol-induced torsade de pointes. Ann Pharmacother 1999; 33(10):1046-1050. PubMed
- Duenas-Laita A, Castro-Villamor MA, Martin-Escudero JC, et al: New clinical manifestations of acute risperidone poisoning (letter). Clin Toxicol 1999; 37(7):893-894. PubMed
- Agelink MW, Zeit T, Baumann B, et al: In vivo cardiovascular effects of the new atypical neuroleptic sertindole. Int J Psychiatry Clin Pract 2001; 5:33-40. PubMed
- Lande G, Drouin E, Gauthier C, et al: Arrhythmogenic effects of sultopride chlorhydrate: clinical and cellular electrophysiological correlation. Ann Fr Anesth Reanim 1992; 11:629-635.
- Sweetman S (Ed): Martindale: The Complete Drug Reference. London: Pharmaceutical Press. Electronic version, MICROMEDEX, Greenwood Village, Colorado, Edition expires 06/2003.
- Product Information: Pamelor(R), nortriptyline. Mallinkroft Inc. St. Louis, MO, 2001. DailyMed
Keep reading about Amitriptyline
Keep reading about Haloperidol
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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