Drug Interaction Report

Disulfiram and Diazepam Rectal: Interaction Details

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

Diazepam Rectal

Diastat Diastat®
+

Disulfiram

Antabuse Antabuse®
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 45 documented Disulfiram interactions, 9 are rated moderate — including this one.
Onset
delayed
Evidence
probable
Severity
Moderate

What happens

An increased risk of central nervous system depression

Interaction Deep Dive

Disulfiram (500 mg daily for two weeks) decreased diazepam clearance by 41% and increased elimination half-life by 37%. Disulfiram does not affect the disposition of oxazepam, lorazepam, and possibly temazepam1.

Why it happens (mechanism)

Decreased diazepam metabolism

Literature reports

1 report — tap to read

a) Concomitant disulfiram and benzodiazepine therapy may potentiate the sedative effects of the benzodiazepine. The metabolic clearance of various benzodiazepines when given concurrently with disulfiram was studied. Determinations of plasma chlordiazepoxide concentrations showed that the parent compound and desmethyl metabolite had a decreased plasma clearance in both healthy and alcoholic patients. The plasma clearance of diazepam decreased in both healthy and alcoholic patients by 41%. There was a corresponding decrease in the active N-desmethyl metabolites of both drugs. Disulfiram increased the half-life of chlordiazepoxide by 84% and diazepam by 37%. The disposition of oxazepam was not altered significantly by disulfiram, but the half-life was increased by 17%. Oxazepam may be the drug of choice in patients on disulfiram who require benzodiazepine therapy 1.

Common questions

Can I take Disulfiram and Diazepam Rectal together?

An increased risk of central nervous system depression Always confirm with your pharmacist or prescriber before making any change.

How serious is the Disulfiram 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.

From our Q&A

Real reader questions about these medications, each personally answered by our pharmacist:

Questions for your pharmacist

  • Does my dose of Disulfiram 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. MacLeod SM, Sellers EM, Giles HG, et al: Interaction of disulfiram with benzodiazepines. Clin Pharmacol Ther 1978; 24:583-589. PubMed
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Beyond drug–drug

These medications also interact with supplements

Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:

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.