Drug Interaction Report

Lonafarnib and Midazolam Injection: Interaction Details

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Lonafarnib

Zokinvy
+

Midazolam Injection

Nayzilam Versed® Injection
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Updated Aug 8, 2026
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Interaction severity
Contraindicated
These should generally not be used together.
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.

Of 146 documented Lonafarnib interactions, 14 are rated contraindicated — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
unspecified
Evidence
probable
Severity
Contraindicated

What happens

Increased midazolam exposure and an increased risk of midazolam-related adverse effects

Interaction Deep Dive

Concomitant use of lonafarnib (a CYP3A inhibitor) with midazolam (a sensitive CYP3A substrate) is contraindicated as it increases exposure of the midazolam which may increase the risk of the midazolam-related adverse reactions, extreme sedation or respiratory depression. If coadministration of other sensitive CYP3A substrates is unavoidable, monitor for adverse reactions and reduce the dosage of midazolam if needed. Temporarily discontinue lonafarnib for 10 to 14 days before and 2 days after administration of midazolam1.

Why it happens (mechanism)

Inhibition of CYP3A-mediated metabolism of midazolam

Literature reports

1 report — tap to read

a) In a clinical study, with coadministration of a single oral dose of 3 mg midazolam with multiple oral doses of 100 mg lonafarnib twice daily for 5 days in healthy subjects, the Cmax and AUC of midazolam were increased by 180% and 639%, respectively 1.

Common questions

Can I take Lonafarnib and Midazolam Injection together?

Increased midazolam exposure and an increased risk of midazolam-related adverse effects Always confirm with your pharmacist or prescriber before making any change.

How serious is the Lonafarnib 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 "probable". Good supporting evidence, though not definitively proven.

Questions for your pharmacist

  • Does my dose of Lonafarnib 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)

  1. Product Information: ZOKINVY(TM) oral capsules, lonafarnib oral capsules. Eiger BioPharmaceuticals Inc (per FDA), Palo Alto, CA, 2024. DailyMed
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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.