Clomipramine 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
Clomipramine
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 clomipramine (Anafranil) are both tricyclic antidepressants, and they work in very similar ways. When you take them together, their effects stack on top of each other. That can mean stronger anticholinergic effects (dry mouth, blurry vision, constipation, trouble urinating), and it can affect your heart's rhythm (called QT prolongation). Because both also raise serotonin, there is a small chance of a serious reaction called serotonin syndrome.
The good news is that your care team can manage this. They may adjust your doses and keep a closer eye on you. Please don't stop or change anything on your own. Talk with your pharmacist or doctor about the best plan for you.
Interaction: Two tricyclic antidepressants with overlapping pharmacology. Combined use produces additive effects across three domains:
- QT prolongation (additive cardiac conduction effects, torsades risk)
- Anticholinergic burden (dry mouth, urinary retention, constipation, delirium)
- Serotonergic effects (risk of serotonin syndrome)
Direction: additive toxicity; not an enzyme induction/inhibition effect. Onset: unspecified. Evidence: theoretical. Severity: major. Management: close supervision with careful dose individualization; consider baseline/follow-up ECG and electrolytes. Monitor for serotonin syndrome (clonus, hyperthermia, autonomic instability); discontinue both agents immediately and give supportive care if it develops.
What happens
An increased risk of QT interval prolongation, an increased risk of anticholinergic effects and an increased risk of serotonin syndrome
Interaction Deep Dive
Taking clomiPRAMINE together with anticholinergic agents that prolong the QT interval and also possess serotonergic activity can lead to cumulative effects on the QT interval as well as combined anticholinergic and serotonergic effects. When clomiPRAMINE is used alongside anticholinergic medications, close monitoring and cautious dose titration are necessary. There have been reports of serotonin syndrome, which is potentially life-threatening, arising in this setting. Should such events develop, clomiPRAMINE along with any accompanying serotonergic drugs should be stopped without delay, and supportive symptomatic care should be started2.
Why it happens (mechanism)
Additive QT interval prolongation; additive anticholinergic effects; additive serotonergic effects
How to manage this interaction
Your care team can manage this combination safely.
- Keep taking both as prescribed unless your prescriber tells you otherwise.
- Your doses may need to be adjusted and individualized by your care team, and they may monitor you more closely (including possible ECG checks on your heart rhythm).
- Watch for anticholinergic effects: dry mouth, blurred vision, constipation, or trouble urinating.
- Seek urgent help for signs of serotonin syndrome: agitation, fast heart rate, fever, sweating, shivering, muscle twitching, or confusion.
Bring up any of these symptoms with your pharmacist or doctor right away.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) Manifestations of serotonin syndrome include neuromuscular disturbances (such as hyperreflexia, tremor, muscle rigidity, clonus, peripheral hypertonicity, and shivering), autonomic hyperactivity (such as tachycardia, mydriasis, diaphoresis, presence of bowel sounds, and diarrhea), and alterations in mental status (such as agitation and delirium). Serotonin syndrome has the potential to be life-threatening. Should serotonin syndrome occur, stop the causative agents and administer supportive care along with any additional therapy that may be required 1.
Common questions
Can I take Clomipramine and Amitriptyline together?
Taking amitriptyline and clomipramine together adds up their heart-rhythm, anticholinergic, and serotonin effects, so your care team should individualize doses and monitor you closely. Keep taking both as prescribed and report symptoms like fever, fast heartbeat, confusion, or severe dry mouth promptly. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Clomipramine 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 Clomipramine and Amitriptyline interaction managed?
Your care team can manage this combination safely. Keep taking both as prescribed unless your prescriber tells you otherwise. Your doses may need to be adjusted and individualized by your care team, and they may monitor you more closely (including possible ECG checks on your heart rhythm). Watch for anticholinergic effects: dry mouth, blurred vision, constipation, or trouble urinating. Seek urgent… 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 Clomipramine 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)
Keep reading about Amitriptyline
Keep reading about Clomipramine
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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