Chloral Hydrate 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
Chloral Hydrate
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.
Amitriptyline (Elavil) and chloral hydrate can each affect the heart's electrical rhythm. Both can stretch out a part of your heartbeat called the QT interval. When you take them together, that effect 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 large studies proving harm. Still, because both touch the same part of the heart, doctors usually prefer not to combine them. Please don't stop either medicine on your own. Just talk with your pharmacist or doctor, and they can look at your heart health and pick the safest plan for you.
Interaction: Additive QTc prolongation from amitriptyline (a TCA) plus chloral hydrate, raising theoretical risk of torsades de pointes and cardiac arrest.
- Mechanism: Pharmacodynamic, not PK. Both agents independently prolong the QTc interval; effects are additive. Neither drug is a prodrug here.
- Direction: Increased cardiotoxicity risk.
- Evidence: Theoretical; no formal interaction studies, but both prolong QTc at therapeutic doses.
- Onset: Unspecified.
- Management: Coadministration is not recommended. If unavoidable, consider ECG monitoring, electrolyte correction (K+, Mg2+), review of other QT-prolonging agents, and dose individualization by the care team.
What happens
An increased risk of cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest)
Interaction Deep Dive
At the recommended therapeutic dose, both chloral hydrate and tricyclic antidepressants have been documented to lengthen the QTc interval21. Although formal studies examining this drug interaction have not been conducted, giving together agents recognized to prolong the QTc interval is advised against.
Why it happens (mechanism)
Additive effects on QT prolongation
How to manage this interaction
The main guidance on file is that combining amitriptyline and chloral hydrate is not recommended, because both can prolong the QT interval.
Here is what typically happens and what you can do:
- Keep taking both exactly as prescribed until you speak with your care team. Do not stop either on your own.
- Your team may prefer an alternative to one of these drugs, or monitor your heart more closely (such as with an ECG) if both are needed.
- Tell your pharmacist or prescriber about any other medicines you take, since some also affect heart rhythm.
- Report fainting, dizziness, or a racing or irregular heartbeat right away.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Chloral Hydrate and Amitriptyline together?
Amitriptyline and chloral hydrate can both prolong the QT interval, so combining them is generally not recommended; ask your pharmacist or doctor whether a safer option or closer heart monitoring is right for you. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Chloral Hydrate 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 Chloral Hydrate and Amitriptyline interaction managed?
The main guidance on file is that combining amitriptyline and chloral hydrate is not recommended, because both can prolong the QT interval. Here is what typically happens and what you can do: Keep taking both exactly as prescribed until you speak with your care team. Do not stop either on your own. Your team may prefer an alternative to one of these drugs, or monitor your heart more closely (such… 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 Chloral Hydrate 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)
- Marshall JB & Forker AD: Cardiovascular effects of tricyclic antidepressant drugs: therapeutic usage, overdose, and management of complications. Am Heart J 1982; 103:401-414. PubMed
- Young JB, Vandermolen LA, & Pratt CM: Torsade de pointes: an unusual mainfestation of chloral hydrate poisoning. Am Heart J 1986; 112:181-184.
Keep reading about Amitriptyline
Keep reading about Chloral Hydrate
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
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