Telaprevir and Midazolam Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Telaprevir
No brand names on recordMidazolam 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 and risk of prolonged sedation or respiratory depression
Interaction Deep Dive
Coadministration of telaprevir, a CYP3A4 inhibitor, and oral midazolam, which is extensively metabolized by CYP3A4, is contraindicated, whereas telaprevir and parenteral midazolam can be coadministered with caution. If concomitant use of telaprevir and parenteral midazolam is required, midazolam should be administered in a setting capable of monitoring for and providing appropriate management of midazolam adverse effects (excessive sedation, confusion, respiratory depression) and a reduced midazolam dose should be considered, especially if more than a single midazolam dose is administered1.
Why it happens (mechanism)
Inhibition of CYP3A-mediated midazolam metabolism
Literature reports
1 report — tap to read
a) In drug interaction studies, the concomitant administration of telaprevir and midazolam in healthy subjects or in patients with chronic hepatitis C resulted in increases in mean midazolam AUC and Cmax. Patients received single doses of IV midazolam 0.5 mg (n=22) or oral midazolam 2 mg (n=21) administered concurrently with telaprevir 750 mg every 8 hours for 9 and 11 days, respectively. Comparing midazolam plus telaprevir versus midazolam administration alone, the ratio estimate for the IV and oral midazolam AUC was 3.4 (90% confidence interval (CI), 3.04 and 3.79) and 8.96 (90% CI, 7.75 to 10.35), respectively. The ratio estimate for IV and oral midazolam Cmax was 1.02 (90% CI, 0.8 to 1.31) and 2.86 (90% CI, 2.52 to 3.25), respectively. The mean change in Cmin was not available 1.
Common questions
Can I take Telaprevir and Midazolam Injection together?
Increased midazolam concentrations and risk of prolonged sedation or respiratory depression Always confirm with your pharmacist or prescriber before making any change.
How serious is the Telaprevir 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 "established". Well documented — supported by controlled studies or strong clinical data.
Questions for your pharmacist
- Does my dose of Telaprevir 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: INCIVEK(TM) film coated oral tablets, telaprevir film coated oral tablets. Vertex Pharmaceuticals Incorporated, Cambridge, MA, 2011.
Keep reading about Telaprevir
Keep reading about Midazolam Injection
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