Haloperidol and Dupilumab Injection: 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
Haloperidol
No brand names on recordDupilumab Injection
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. Haloperidol is an antipsychotic that your body breaks down using an enzyme called CYP2D6. When inflammation in the body is high, that enzyme can work more slowly on its own, and treating that inflammation (as Dupixent does) may shift how much haloperidol you have in your system. The concern is that haloperidol levels could rise, which can mean more side effects like drowsiness, stiffness, or changes in your heart's rhythm (a QTc effect).
The good news: this is a theoretical concern, not something proven to happen often. Your care team can manage it easily by watching how you feel and adjusting your haloperidol dose if needed. Don't stop either medicine on your own, just talk with your doctor or pharmacist.
Mechanism: Theoretical reduction in CYP2D6-mediated clearance of haloperidol, increasing haloperidol exposure. Neither agent is a prodrug; haloperidol is the affected object drug, so higher exposure means enhanced pharmacologic and adverse effects.
- Direction: Increased haloperidol AUC/Cmax, raising risk of QTc prolongation, EPS, and sedation.
- Evidence: Theoretical (biologics like dupilumab may normalize cytokine-suppressed CYP activity); magnitude not quantified.
- Onset: Unspecified.
- Management: Monitor for signs of increased or prolonged haloperidol effect; consider ECG/QTc monitoring per clinical judgment; reduce haloperidol dose as needed.
What happens
Increased haloperidol exposure and an increased risk of haloperidol-related adverse events, including QTc interval prolongation
Interaction Deep Dive
When haloperidol is given together with CYP2D6 inhibitors, haloperidol exposure may rise, potentially leading to a greater incidence of haloperidol-associated adverse events, such as prolongation of the QTc interval. For patients receiving haloperidol alongside these agents, monitoring for indications of heightened or extended pharmacologic effects of haloperidol is advised, with a reduction in the haloperidol dose made if considered necessary1.
Why it happens (mechanism)
Inhibition of CYP2D6-mediated metabolism of haloperidol
How to manage this interaction
This is manageable with monitoring. Keep taking both medicines exactly as prescribed unless your doctor tells you otherwise.
- Your care team may watch you more closely for stronger or longer-lasting haloperidol effects (extra drowsiness, muscle stiffness, restlessness, or lightheadedness).
- Your haloperidol dose may need to be adjusted and individualized by your care team if they see signs it is building up.
- Because haloperidol can affect heart rhythm (QTc), your doctor may check an ECG if they feel it's needed.
Tell your pharmacist or prescriber about any new or worsening symptoms, and mention all the medicines you take.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) QTc prolongation has been reported when haloperidol was administered together with a combination of the metabolic inhibitors ketoconazole (a CYP3A4 inhibitor) (400 mg/day) and PARoxetine (a CYP2D6 inhibitor) (20 mg/day) 1.
Common questions
Can I take Haloperidol and Dupilumab Injection together?
Combining dupilumab with haloperidol may theoretically raise haloperidol levels and side effects, including heart-rhythm (QTc) changes. Keep taking both as prescribed and let your care team monitor you and adjust the haloperidol dose if needed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Haloperidol and Dupilumab Injection 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 Haloperidol and Dupilumab Injection interaction managed?
This is manageable with monitoring. Keep taking both medicines exactly as prescribed unless your doctor tells you otherwise. Your care team may watch you more closely for stronger or longer-lasting haloperidol effects (extra drowsiness, muscle stiffness, restlessness, or lightheadedness). Your haloperidol dose may need to be adjusted and individualized by your care team if they see signs it is bui… 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 Haloperidol or Dupilumab Injection 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: HALDOL(R) Decanoate 100 intramuscular injection, haloperidol decanoate intramuscular injection. Janssen Pharmaceuticals Inc (per FDA), Titusville, NJ, 2025.
Keep reading about Haloperidol
Keep reading about Dupilumab Injection
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