Delavirdine and Midazolam Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Delavirdine
Midazolam 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.
What happens
Increased midazolam concentrations
Interaction Deep Dive
Delavirdine and midazolam are both metabolized by the CYP3A4 enzyme system. Competition for this pathway could result in inhibition of midazolam metabolism, creating the potential for midazolam toxicity (excessive sedation, confusion). Concurrent administration of delavirdine and midazolam is contraindicated1.
Why it happens (mechanism)
Inhibition by delavirdine of cytochrome P450 3A4-mediated midazolam metabolism
Common questions
Can I take Delavirdine and Midazolam Injection together?
Increased midazolam concentrations Always confirm with your pharmacist or prescriber before making any change.
How serious is the Delavirdine and Midazolam Injection interaction?
It is rated contraindicated. These should generally not be used together.
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 "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Delavirdine or Midazolam 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: RESCRIPTOR(R) oral tablets, delavirdine mesylate oral tablets. Pfizer,Inc, New York, NY, 2006.
Keep reading about Delavirdine
Keep reading about Midazolam Injection
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