Brompheniramine and Buprenorphine: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Brompheniramine
Buprenorphine
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 brompheniramine (an antihistamine for allergy symptoms) along with buprenorphine (for pain or for opioid treatment). Taking them together can add up in two ways. First, both can gently nudge a brain chemical called serotonin, and if it climbs too high you could feel a rare reaction with symptoms like agitation, shivering, sweating, a fast heartbeat, or muscle twitching. Second, both can slow down your gut, so together they may cause constipation that in rare cases becomes serious.
This concern is mostly theoretical, and many people take both safely. Your care team can watch for these signs and manage this, so keep taking both as prescribed and let them know how you feel.
Effect: Additive risk of serotonin syndrome plus additive reduction in GI motility (constipation progressing to paralytic ileus). Brompheniramine also contributes anticholinergic load, raising risk of urinary retention and constipation.
Direction/mechanism: Both agents have serotonergic activity; buprenorphine (opioid) and brompheniramine (anticholinergic antihistamine) both slow gut motility. Neither is a relevant prodrug here. Additive PD interaction, not a PK/enzyme effect.
Evidence: Theoretical; severity major; onset unspecified.
- Observe especially at initiation and dose changes.
- Monitor for serotonin syndrome (autonomic instability, clonus, hyperthermia, mental status change); discontinue if suspected.
- Monitor bowel/bladder function; treat constipation proactively.
What happens
An increased risk of serotonin syndrome and an increased risk of paralytic ileus
Interaction Deep Dive
When buprenorphine is given together with serotonergic agents, such as SSRIs, serotonin and norepinephrine reuptake inhibitors, tricyclic antidepressants, triptans, 5-HT3 receptor antagonists, medications that interfere with serotonin metabolism, and other substances acting on the serotonergic system, serotonin syndrome can occur. Watch for indications of severe constipation, since this may progress to paralytic ileus. Should combined use of buprenorphine and serotonergic agents that have anticholinergic properties be required, monitor the patient, particularly at the start of therapy and when doses are being modified231.
Why it happens (mechanism)
Additive serotonergic effects; additive effects on gastric motility
How to manage this interaction
Your care team can manage this combination safely with a little extra attention. Here's what they typically do and what you can do:
- Keep taking both as prescribed unless your prescriber tells you otherwise.
- Doses may be adjusted and individualized by your team, and they may watch you more closely at the start and after any change.
- Watch for signs of serotonin syndrome: agitation, confusion, sweating, shivering, fast heartbeat, muscle twitching or stiffness. Get medical help right away if these appear.
- Watch for severe constipation or trouble urinating, and report it, since serious constipation needs prompt attention.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Brompheniramine and Buprenorphine together?
Brompheniramine and buprenorphine can add up to raise the rare risk of serotonin syndrome and can worsen constipation, so watch for those signs and stay in touch with your care team, especially when starting or changing doses. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Brompheniramine and Buprenorphine 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 Buprenorphine interaction managed?
Your care team can manage this combination safely with a little extra attention. Here's what they typically do and what you can do: Keep taking both as prescribed unless your prescriber tells you otherwise. Doses may be adjusted and individualized by your team, and they may watch you more closely at the start and after any change. Watch for signs of serotonin syndrome: agitation, confusion, sweati… 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 Buprenorphine 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 (3)
- Product Information: BRIXADI(TM) subcutaneous extended-release injection, buprenorphine subcutaneous extended-release injection. Braeburn Inc (per FDA), Plymouth Meeting, PA, 2023. DailyMed
- Product Information: BUTRANS(R) transdermal system patch, buprenorphine transdermal system patch. Purdue Pharma L.P. (per FDA), Stamford, CT, 2016. DailyMed
- Product Information: SUBOXONE(R) sublingual film, buprenorphine naloxone sublingual film. Indivior Inc (per FDA), Richmond, VA, 2017. DailyMed
Keep reading about Brompheniramine
Keep reading about Buprenorphine
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