Telithromycin and Midazolam Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Telithromycin
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 risk for benzodiazepine toxicity (CNS depression, sedation, dizziness, ataxia, weakness, decreased cognition or motor performance)
Interaction Deep Dive
Telithromycin, a ketolide antibiotic, is a potent inhibitor of CYP3A4, the hepatic enzyme responsible for midazolam metabolism, and may increase midazolam exposure in patients using concurrent therapy. The area under the concentration-time curve (AUC) increased 2-fold in patients receiving telithromycin and intravenous midazolam and 6-fold in patients receiving telithromycin and oral midazolam. The potential for increased midazolam exposure warrants careful monitoring of CNS side effects. Reduced midazolam dosing may be appropriate1.
Why it happens (mechanism)
Telithromycin inhibition of CYP3A4-mediated midazolam metabolism
Common questions
Can I take Telithromycin and Midazolam Injection together?
Increased risk for benzodiazepine toxicity (CNS depression, sedation, dizziness, ataxia, weakness, decreased cognition or motor performance) Always confirm with your pharmacist or prescriber before making any change.
How serious is the Telithromycin and Midazolam Injection interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Telithromycin 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 anything you'd monitor while I'm on both?
References (1)
- Product Information: KETEK(R) ORAL TABLET, telithromycin oral tablet. Aventis Pharmaceuticals Inc. Kansas City, MO, 2005. DailyMed
Keep reading about Telithromycin
Keep reading about Midazolam Injection
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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:
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