Abemaciclib and Clomipramine: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 10, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Clomipramine
Abemaciclib
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.
Here's what's going on. Clomipramine (Anafranil) is broken down in your body partly by a liver enzyme called CYP1A2. Abemaciclib (Verzenio) can slow that enzyme down. When that happens, clomipramine can build up higher than expected, which may mean more of its usual side effects, like drowsiness, dry mouth, constipation, dizziness, or a faster heartbeat.
I want to be clear that this is a theoretical concern, based on how these drugs work rather than lots of real-world reports. The good news is your care team can manage it easily by keeping an eye on how you're doing and adjusting your clomipramine dose if needed. Please don't stop either medicine on your own, just talk with your doctor or pharmacist.
Mechanism: Abemaciclib may inhibit CYP1A2-mediated metabolism of clomipramine, increasing clomipramine exposure (AUC/Cmax). Clomipramine is an active drug, not a prodrug, so inhibition raises its pharmacologic and toxic effects.
- Direction: Increased clomipramine exposure, greater risk of anticholinergic, sedative, and cardiac (QT/conduction) effects.
- Evidence: Theoretical; magnitude not quantified.
- Onset: Unspecified.
- Management: Individualize dosing; a lower clomipramine dose may be warranted. Monitor for TCA toxicity and consider plasma level monitoring where available. On withdrawal of the inhibitor, an upward clomipramine dose adjustment may be needed.
What happens
Increased clomiPRAMINE exposure
Interaction Deep Dive
When clomiPRAMINE is taken together with inhibitors of CYP1A2, clomiPRAMINE exposure may rise, so doses lower than those typically prescribed for clomiPRAMINE or for the companion drug may be needed. In addition, if either of these agents is stopped during combined therapy, a higher dose of clomiPRAMINE may become necessary. Monitoring of clomiPRAMINE exposure is advisable whenever it is given alongside another agent recognized as a CYP1A2 inhibitor1.
Why it happens (mechanism)
Inhibition of CYP1A2-mediated metabolism of clomiPRAMINE
How to manage this interaction
The takeaway: this is manageable. Keep taking both medicines exactly as prescribed unless your care team tells you otherwise.
- Your clomipramine dose may need to be adjusted and individualized by your care team, and they may monitor you more closely while you're on both.
- If your abemaciclib is ever stopped, your clomipramine dose may need to be raised again, so this works both ways.
- Watch for and report side effects like strong drowsiness, dry mouth, constipation, dizziness, trouble urinating, or a racing or irregular heartbeat.
- Talk with your pharmacist or prescriber before making any changes.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Abemaciclib and Clomipramine together?
Abemaciclib may raise clomipramine levels, so watch for more clomipramine side effects and let your care team adjust the dose and monitor you. Don't change either medicine on your own. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Abemaciclib and Clomipramine 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 Abemaciclib and Clomipramine interaction managed?
The takeaway: this is manageable. Keep taking both medicines exactly as prescribed unless your care team tells you otherwise. Your clomipramine dose may need to be adjusted and individualized by your care team, and they may monitor you more closely while you're on both. If your abemaciclib is ever stopped, your clomipramine dose may need to be raised again, so this works both ways. Watch for and r… 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.
Questions for your pharmacist
- Does my dose of Abemaciclib or Clomipramine 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: ANAFRANIL(TM) oral capsules, clomipramine hydrochloride oral capsules. SpecGx LLC (per Dailymed), Webster Groves, MO, 2024. DailyMed
Keep reading about Clomipramine
Keep reading about Abemaciclib
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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:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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