Doxazosin and Iloperidone: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Iloperidone
Doxazosin
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.
What happens
Increased risk of symptomatic hypotension
Interaction Deep Dive
Avoid coadministration of iloperidone with alpha-adrenergic blocking agents as it may result in symptomatic hypotension. Adjust medications that affect blood pressure as needed1.
Why it happens (mechanism)
Additive effects on blood pressure
Common questions
Can I take Doxazosin and Iloperidone together?
Increased risk of symptomatic hypotension Always confirm with your pharmacist or prescriber before making any change.
How serious is the Doxazosin and Iloperidone 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 strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Doxazosin or Iloperidone 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: FANAPT(R) oral tablets, iloperidone oral tablets. Vanda Pharmaceuticals Inc (per FDA), Washington, DC, 2024. DailyMed
Keep reading about Iloperidone
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