Brompheniramine and Acetaminophen And Codeine: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jun 30, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Acetaminophen And Codeine
Brompheniramine
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.
You've been prescribed two medicines that can affect your body in overlapping ways. Codeine (an opioid pain reliever) can slow down your gut, and brompheniramine (an antihistamine) can do the same because it has drying, anticholinergic effects. Used together, they may make constipation worse or cause trouble emptying your bladder. In rare cases the gut can slow so much that it nearly stops. There's also a small, mostly theoretical chance of a reaction called serotonin syndrome.
The good news is this is manageable. Watch for hard constipation, belly pain, or trouble urinating, and let your care team know. Your doctor or pharmacist can adjust things and keep an eye on you.
Effect: Additive risk of severe constipation/urinary retention progressing to paralytic ileus (additive anticholinergic and opioid effects on GI motility) and a theoretical additive serotonergic risk (serotonin syndrome).
- Direction: Both agents contribute; codeine is a CYP2D6 prodrug for morphine, but the concern here is pharmacodynamic (additive), not PK.
- Onset: Unspecified; highest during initiation and dose changes.
- Evidence: Theoretical.
- Management: Monitor for urinary retention, severe constipation, and serotonin syndrome signs (agitation, clonus, hyperthermia, autonomic instability). Consider prophylactic bowel regimen. Discontinue codeine if serotonin syndrome is suspected.
What happens
Increased risk of paralytic ileus; increased risk of serotonin syndrome
Interaction Deep Dive
Concomitant use of opioids, such as codeine, with serotonergic drugs has resulted in serotonin syndrome. Additionally, the concomitant use of codeine with anticholinergic drugs may increase the risk of urinary retention and severe constipation, which may lead to paralytic ileus. If concomitant use is needed, closely monitor the patient for urinary retention, severe constipation, and signs and symptoms of serotonin syndrome1. during treatment initiation and dose adjustment. Discontinue codeine if serotonin syndrome is suspected 2.
Why it happens (mechanism)
Additive effects on gastric motility; additive serotonergic effects
How to manage this interaction
Keep taking both medicines as prescribed unless your care team tells you otherwise. This interaction can usually be managed with monitoring.
- Watch for hard or absent bowel movements, stomach bloating or pain, and trouble urinating.
- Also note any confusion, agitation, fast heartbeat, sweating, shivering, or muscle twitching, which can signal serotonin syndrome.
- Your team may add a stool softener or laxative and monitor you more closely, especially when starting or changing doses.
- Report symptoms promptly to your pharmacist or prescriber; the codeine may be stopped if serotonin syndrome is suspected.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Brompheniramine and Acetaminophen And Codeine together?
Taking codeine with brompheniramine can add up to worsen constipation and urinary retention (rarely a stalled gut) and carries a small theoretical serotonin risk; keep taking both as prescribed but watch for these symptoms and tell your care team. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Brompheniramine and Acetaminophen And Codeine 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 Brompheniramine and Acetaminophen And Codeine interaction managed?
Keep taking both medicines as prescribed unless your care team tells you otherwise. This interaction can usually be managed with monitoring. Watch for hard or absent bowel movements, stomach bloating or pain, and trouble urinating. Also note any confusion, agitation, fast heartbeat, sweating, shivering, or muscle twitching, which can signal serotonin syndrome. Your team may add a stool softener or… 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 Brompheniramine or Acetaminophen And Codeine 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 (2)
- Product Information: Codeine sulfate oral tablets, codeine sulfate oral tablets. West-Ward Pharmaceuticals Corp (per DailyMed), Eatontown, NJ, 2016. DailyMed
- Product Information: CARISOPRODOL, ASPIRIN, CODEINE PHOSPHATE oral tablets, carisoprodol, aspirin, codeine phosphate oral tablets. Ingenus Pharmaceuticals LLC (per DailyMed), Orlando, FL, 2021. DailyMed
Keep reading about Acetaminophen And Codeine
Keep reading about Brompheniramine
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.
Check another combination
Our instant two-drug interaction checker is almost here.
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