Drug Interaction Report

Amprenavir and Diazepam Rectal: Interaction Details

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

Amprenavir

No brand names on record
+

Diazepam Rectal

Diastat Diastat®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Updated Aug 8, 2026
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Interaction severity
Moderate
Can be significant — usually manageable with monitoring.
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 79 documented Amprenavir interactions, 23 are rated moderate — including this one.
Onset
delayed
Evidence
probable
Severity
Moderate

What happens

An increased risk of diazepam toxicity (excessive sedation, confusion)

Interaction Deep Dive

Serum concentrations of diazepam may be elevated by the concurrent administration of amprenavir. Currently no interaction study has been conducted. Amprenavir and diazepam are both metabolized by cytochrome P450 3A4 enzymes, in addition to amprenavir inhibiting CYP3A4. Competition for metabolism and/or inhibition of metabolism could result in an increased plasma concentration of diazepam1.

Why it happens (mechanism)

Inhibition of cytochrome P450 3A4-mediated diazepam metabolism by amprenavir

Common questions

Can I take Amprenavir and Diazepam Rectal together?

An increased risk of diazepam toxicity (excessive sedation, confusion) Always confirm with your pharmacist or prescriber before making any change.

How serious is the Amprenavir and Diazepam Rectal 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 Amprenavir or Diazepam Rectal 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)

  1. Product Information: Agenerase(R), amprenavir. Glaxo Wellcome Inc. Research Triangle Park, NC, 2000.
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Beyond drug–drug

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major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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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.