Acetaminophen And Codeine and Halazepam: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 1, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Acetaminophen And Codeine
Halazepam
No brand names on record
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.
Your pain medicine has codeine, which is an opioid, and halazepam is a benzodiazepine (a calming, anti-anxiety medicine). Both of these slow down your brain and breathing. When you take them together, those effects add up. That can mean very deep sleepiness, slow or shallow breathing, low blood pressure, and in serious cases it can be life-threatening.
This does not mean you can't ever use both. It means your care team wants to keep the doses low, the time short, and watch you closely. Please don't stop either medicine on your own. Talk with your pharmacist or doctor so they can make sure this combination is safe for you, and ask whether keeping naloxone on hand is a good idea.
Effect: Additive CNS and respiratory depression from combining codeine (opioid) with halazepam (benzodiazepine), raising risk of hypotension, profound sedation, respiratory depression, coma, and death. This is a pharmacodynamic interaction, not enzymatic; neither agent's activation is the driver here.
- Direction: Increased depressant effect (additive).
- Onset: Unspecified; expect with overlapping exposure.
- Evidence: Theoretical, but severity rated major (class effect, FDA boxed-warning territory).
- Management: Reserve co-prescribing for when alternatives are inadequate; use lowest effective doses and shortest duration; monitor for sedation and respiratory depression; consider prescribing naloxone.
What happens
An increased risk of hypotension, respiratory depression, profound sedation, coma, and death
Interaction Deep Dive
Concomitant use of codeine with benzodiazepines can increase the risk of hypotension, respiratory depression, profound sedation, coma and death. Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Follow patients closely for signs of respiratory depression and sedation. If concomitant use is warranted, consider prescribing naloxone for the emergency treatment of opioid overdose134.
Why it happens (mechanism)
Additive CNS depression
How to manage this interaction
If your prescriber has you on both, the goal is to use them safely, not necessarily to avoid them entirely.
- Keep taking both as prescribed unless your care team tells you otherwise.
- Your team will typically use the lowest doses for the shortest time needed.
- They may monitor you more closely for heavy drowsiness, confusion, or slow/shallow breathing.
- Ask whether having naloxone at home makes sense as a safety backup.
- Avoid alcohol and other sedating medicines, and tell your pharmacist about everything you take.
Call your prescriber right away if you notice unusual sleepiness or trouble breathing.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
4 reports — tap to read
a) In one study, emergency department visits related to nonmedical use that took place between 2004 and 2011 and involved both opioid analgesics and benzodiazepines rose significantly from 11 to 34.2 per 100,000. Deaths from drug overdose attributable to both prescribed and higher than prescribed doses of these two drug classes likewise increased significantly from 0.6 to 1.7 per 100,000, and overdose deaths involving benzodiazepines rose significantly from 18% to 31% 2.
b) In a prospective cohort study, the rate of overdose deaths associated with the dispensing of both opioid analgesics and benzodiazepines was 10 times greater than that seen with the dispensing of opioid analgesics alone (7 vs 0.7 per 10,000 person years) 2.
c) In a cohort study using data from 2004 to 2009, the risk of fatal overdose increased significantly by 2.33 fold among patients taking opioid analgesics who had a history of a benzodiazepine prescription, and increased by 3.86 fold in those with a current benzodiazepine prescription, compared with patients taking opioid analgesics who had no history of a benzodiazepine prescription. The risk of drug overdose deaths rose as daily doses of benzodiazepines increased 2.
d) Observational studies have shown that using opioid analgesics together with benzodiazepines raises the risk of drug-related mortality compared with using opioid analgesics alone. Given their comparable pharmacological properties, it is reasonable to anticipate a similar risk when other CNS depressant drugs are used concurrently with opioid analgesics 34.
Common questions
Can I take Acetaminophen And Codeine and Halazepam together?
Codeine and halazepam both depress breathing and alertness, so together they can be dangerous; keep doses low and short, watch for extreme drowsiness or slow breathing, and ask your care team about keeping naloxone available. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen And Codeine 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 is the Acetaminophen And Codeine and Halazepam interaction managed?
If your prescriber has you on both, the goal is to use them safely, not necessarily to avoid them entirely. Keep taking both as prescribed unless your care team tells you otherwise. Your team will typically use the lowest doses for the shortest time needed. They may monitor you more closely for heavy drowsiness, confusion, or slow/shallow breathing. Ask whether having naloxone at home makes sense… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Acetaminophen And Codeine 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 (4)
- Product Information: CARISOPRODOL, ASPIRIN, CODEINE PHOSPHATE oral tablets, carisoprodol, aspirin, codeine phosphate oral tablets. Ingenus Pharmaceuticals LLC (per DailyMed), Orlando, FL, 2021. DailyMed
- 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.
- Product Information: Codeine sulfate oral solution, codeine sulfate oral solution. Hikma Pharmaceuticals USA Inc(per FDA), Berkeley Heights, NJ, 2023. DailyMed
- Product Information: Codeine sulfate oral tablets, codeine sulfate oral tablets. Hikma Pharmaceuticals USA Inc. (per FDA), Berkeley Heights, NJ, 2023. DailyMed
Keep reading about Acetaminophen And Codeine
Keep reading about Halazepam
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