Acetaminophen And Codeine and Tetrazepam: 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
Tetrazepam
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 contains codeine, an opioid, and tetrazepam is a benzodiazepine (a muscle relaxer and calming medicine). Both of these slow down your brain and breathing. When you take them together, that slowing effect adds up. This can make you very sleepy, lower your blood pressure, and in serious cases make your breathing dangerously slow. That is why this combination is taken seriously.
The good news is your care team can manage this. If they decide you need both, they will usually use the lowest doses for the shortest time and keep a close eye on you. Please don't stop either medicine on your own, just talk with your doctor or pharmacist about it.
Effect: Additive CNS and respiratory depression from combining codeine (opioid) with tetrazepam (benzodiazepine). Risk includes hypotension, profound sedation, respiratory depression, coma, and death.
Mechanism: Pharmacodynamic, additive depression of the CNS and respiratory drive. Neither is a prodrug issue here; codeine is a mu-opioid agonist and tetrazepam a GABA-A modulator, and their depressant effects summate.
- Direction: Increased depressant effect (both agents).
- Evidence: Theoretical, but consistent with a well-established class effect; severity major.
- Onset: Unspecified.
- Management: Reserve for patients without adequate alternatives; use minimum effective dose and duration; monitor for sedation/respiratory depression; consider co-prescribing naloxone.
What happens
An increased risk of hypotension, respiratory depression, profound sedation, coma, and death
Interaction Deep Dive
Using codeine together with benzodiazepines may heighten the likelihood of hypotension, respiratory depression, deep sedation, coma, and death. Prescribing these agents concurrently should be limited to patients for whom other treatment choices are insufficient. Keep doses and treatment durations at the lowest levels necessary. Monitor patients carefully for indications of sedation and respiratory depression. When combined use is justified, consider prescribing naloxone for emergency management of opioid overdose134.
Why it happens (mechanism)
Additive CNS depression
How to manage this interaction
If your team decides you need both medicines, here is how they typically keep you safe:
- They may reserve this combination for when other options aren't enough, and use the lowest doses for the shortest time needed.
- They may monitor you more closely for signs of heavy sedation or slowed breathing.
- They may consider prescribing naloxone (a rescue medicine for opioid overdose) to keep on hand.
What you can do: Keep taking both exactly as prescribed unless told otherwise. Tell someone at home the warning signs (extreme drowsiness, confusion, very slow or shallow breathing) and get medical help right away if they happen. Ask your pharmacist or doctor before adding alcohol or any other sedating medicine.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
4 reports — tap to read
a) One study found that between 2004 and 2011, the rate of emergency department visits related to nonmedical use and involving both opioid analgesics and benzodiazepines rose significantly from 11 to 34.2 per 100,000. Drug overdose deaths attributable to prescribed and higher than prescribed doses of both drug classes likewise rose significantly from 0.6 to 1.7 per 100,000, and overdose deaths caused by benzodiazepines rose significantly from 18% to 31% 2.
b) In a prospective cohort study, the rate of overdose deaths involving the dispensing of both opioid analgesics and benzodiazepines was 10 times greater than that seen with the dispensing of opioid analgesics alone (7 versus 0.7 per 10,000 person years) 2.
c) In a cohort study using data from 2004 to 2009, the risk of fatal overdose rose significantly by 2.33 fold among patients taking opioid analgesics who had a history of a benzodiazepine prescription, and rose by 3.86 fold among those with a current benzodiazepine prescription, when compared with patients taking opioid analgesics who had no history of a benzodiazepine prescription. The risk of drug overdose deaths grew as daily benzodiazepine doses increased 2.
d) Observational studies have shown that using opioid analgesics together with benzodiazepines raises the risk of drug-related mortality relative to using opioid analgesics alone. Given comparable pharmacological properties, it is reasonable to anticipate a similar risk when other CNS depressant drugs are used together with opioid analgesics 34.
Common questions
Can I take Acetaminophen And Codeine and Tetrazepam together?
Codeine and tetrazepam both depress the brain and breathing, so together they raise the risk of dangerous sedation and slowed breathing. Use only if your care team says it's needed, at the lowest dose, with close monitoring, and know the overdose warning signs. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen And Codeine and Tetrazepam 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 Tetrazepam interaction managed?
If your team decides you need both medicines, here is how they typically keep you safe: They may reserve this combination for when other options aren't enough, and use the lowest doses for the shortest time needed. They may monitor you more closely for signs of heavy sedation or slowed breathing. They may consider prescribing naloxone (a rescue medicine for opioid overdose) to keep on hand. What y… 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 Tetrazepam 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
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