Drug Interaction Report

Morphine Injection and Halazepam: Interaction Details

A pharmacist-reviewed analysis of the Morphine Injection and Halazepam interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

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

Halazepam

No brand names on record
+

Morphine Injection

Astramorph® PF Duramorph Duramorph® Infumorph Infumorph® Kadian Mitigo MS Contin
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
LinkedIn
Interaction severity
Major
Potentially serious — often needs a change or close 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 437 documented Morphine Injection interactions, 409 are rated major — 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
Major

What happens

Increased risk of profound sedation, respiratory depression, hypotension, coma and death

Interaction Deep Dive

Reserve the concomitant use of morphine and CNS depressants for patients in whom alternatives are inadequate. If concomitant use is necessary, use the lowest dose and shortest duration needed. Consider using a lower dose of morphine or the CNS depressant and closely monitor for sedation and respiratory depression432. If morphine/naltrexone combination is being initiated, start at one-third to one-half of the usual morphine/naltrexone dose 5. If Morphabond ER(TM) is being initiated, start at the lowest possible dose, 15 mg every 12 hours, and consider using a lower dosage of the concomitant CNS depressant 6. The risk of opioid overdose is increased with concurrent use of morphine with CNS depressants. Consider prescribing naloxone for the emergency treatment of opioid overdose 1.

Why it happens (mechanism)

Additive CNS depression effects

Literature reports

3 reports — tap to read

a) In a study, the rate of nonmedical use-related emergency department visits occurring between 2004 and 2011 and involving opioid analgesics and benzodiazepines significantly increased from 11 to 34.2 per 100,000. Drug overdose deaths due to prescribed and greater than prescribed doses of both drug classes also significantly increased from 0.6 to 1.7 per 100,000, and overdoses deaths due to benzodiazepines significantly increased from 18% to 31% 7.

b) In a prospective cohort study, the rate of overdose deaths involving the dispensing of both opioid analgesics and benzodiazepines was 10 times higher compared with dispensing of opioid analgesics alone (7 vs 0.7 per 10,000 person years) 7.

c) In a cohort study of data from 2004 to 2009, the risk of fatal overdose significantly increased by 2.33 fold in patients taking opioid analgesics with a history of a benzodiazepine prescription and increased by 3.86 fold in those with a current benzodiazepine prescription compared with those taking opioid analgesics without a history of a benzodiazepine prescription. The risk of drug overdose deaths increased with increasing daily doses of benzodiazepines 7.

Common questions

Can I take Morphine Injection and Halazepam together?

Increased risk of profound sedation, respiratory depression, hypotension, coma and death Always confirm with your pharmacist or prescriber before making any change.

How serious is the Morphine Injection and Halazepam interaction?

It is rated major. Potentially serious — often needs a change or close monitoring.

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 Morphine Injection or Halazepam 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 (7)

  1. Product Information: MS CONTIN(R) oral extended-release tablets, morphine sulfate oral extended-release tablets. Purdue Pharma LP (per FDA), Stamford, CT, 2023. DailyMed
  2. Product Information: DURAMORPH intravenous, epidural, intrathecal injection, morphine sulfate intravenous, epidural, intrathecal injection. Hikma Pharmaceuticals USA Inc (Per FDA), Berkeley, NJ, 2023. DailyMed
  3. Product Information: KADIAN(R) oral extended-release capsules, morphine sulfate oral extended-release capsules. Allergan USA, Inc (per FDA), Irvine, CA, 2016. DailyMed
  4. Product Information: ARYMO(TM) ER oral extended-release tablets, morphine sulfate oral extended-release tablets. Egalet US Inc (per manufacturer), Wayne, PA, 2017. DailyMed
  5. Product Information: EMBEDA(R) oral extended-release capsules, morphine sulfate naltrexone HCl oral extended-release capsules. Pfizer Inc. (per FDA), New York, NY, 2016. DailyMed
  6. Product Information: MORPHABOND(TM) ER oral extended-release tablets, morphine sulfate oral extended-release tablets. Daiichi Sankyo Inc (per FDA), Basking Ridge, NJ, 2018. DailyMed
  7. US Food and Drug Administration (FDA): Drug Safety Communications: FDA warns about serious risks and death when combining opioid pain or cough medicines with benzodiazepines; requires its strongest warning. US Food and Drug Administration (FDA). Silver Spring, MD. 2016.
Was this write-up helpful?
Halazepam

Keep reading about Halazepam

All Halazepam interactions (22)
Also serious with: Esketamine Nasal Spray Nalbuphine Injection Fentanyl Transdermal Patch Metoclopramide Injection
Morphine Injection

Keep reading about Morphine Injection

All Morphine Injection interactions (437) Morphine Injection drug information
Also serious with: Rasagiline Procarbazine Phenelzine Ozanimod
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:

Halazepam + Activated Charcoal Grapefruit Adrue Ashwagandha Coffee Charcoal European Mandrake Glucomannan Guar Gum + 17 more

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

Check another combination

Our instant two-drug interaction checker is almost here.

Coming soon

The instant two-drug checker is on its way.

In the meantime, browse the directory below to look up any drug and see its documented interactions.

Still have questions about this combination?

Every question gets a real answer from a licensed pharmacist — free, and usually within a day.

Ask the pharmacist
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.