Buprenorphine and Quetiapine: 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
Buprenorphine
Quetiapine
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.
Both buprenorphine (a pain and addiction-treatment medicine) and quetiapine (Seroquel, used for mood and sleep issues) can slow your breathing and make you very sleepy. Taken together, those effects can add up, which raises the risk of heavy sedation and dangerously slow breathing. Both can also affect your heart's rhythm and slow down your gut, which can lead to bad constipation or trouble emptying your bladder.
This sounds scary, but please don't stop either medicine on your own. Your care team can manage this safely by choosing the right doses and watching you more closely. Talk with your pharmacist or doctor about any extra sleepiness, and ask whether keeping naloxone on hand makes sense for you.
Additive toxicity, no prodrug involved. Combining buprenorphine (partial mu-opioid agonist) with quetiapine produces overlapping pharmacodynamic effects:
- Additive QT prolongation (both agents affect cardiac repolarization).
- Additive CNS and respiratory depression, with risk of profound sedation, coma, and death.
- Additive reduction in GI motility, raising risk of severe constipation or paralytic ileus, plus urinary retention.
Evidence: probable; supported by epidemiologic overdose-death data in MAT patients. Severity: major. Management: avoid where feasible; prefer tapering/lowest effective dose. If combined, monitor sedation, respiratory rate, constipation, urinary retention, and consider ECG for QT. Consider alternatives for anxiety/insomnia and co-prescribe naloxone. Do not withhold MAT solely due to this interaction.
What happens
An increased risk of QT interval prolongation, an increased risk of CNS and respiratory depression and an increased risk of paralytic ileus
Interaction Deep Dive
Concurrent administration of buprenorphine with agents capable of prolonging the QT interval should be avoided. Combining these drugs also heightens the likelihood of respiratory depression, profound sedation, coma, and death. Discontinuing CNS depressants is favored rather than using them together. Depending on the situation, it may be suitable to observe the patient in a higher level of care or to institute a taper. In other circumstances, slowly weaning a patient off a prescribed CNS depressant, or reducing to the smallest effective dose, may be the appropriate approach. When simultaneous use cannot be avoided, watch for urinary retention, severe constipation, sedation, and respiratory depression; think about alternative treatments for anxiety or insomnia, and give strong consideration to prescribing naloxone for emergency management of opioid overdose1. A Swedish epidemiological study found that patients on methadone- or buprenorphine-based medication-assisted treatment (MAT) who also took benzodiazepines or other CNS depressants (for instance, medications for insomnia) have a greater risk of death. Analysis of pooled nationwide death certificate data spanning 2010 to 2014 showed that concomitant CNS depressant use was present in most overdose deaths involving buprenorphine and methadone. Whether the risk of fatal overdose associated with concurrent CNS depressant drugs varied between buprenorphine and methadone remains unknown 2.
Why it happens (mechanism)
Additive QT interval prolongation; additive CNS depression; additive effects on gastric motility
How to manage this interaction
The safest approach is often to avoid using both together, but this must be decided with your prescriber, never by stopping a medicine yourself.
- Keep taking both as prescribed until your care team advises otherwise.
- Your team may lower a dose, taper one medicine, or monitor you more closely, sometimes with an ECG to check your heart rhythm.
- Ask whether an alternative for anxiety or sleep might be safer than quetiapine.
- Strongly consider having naloxone at home for emergencies.
Call your pharmacist or doctor right away if you notice heavy drowsiness, slow or shallow breathing, severe constipation, or trouble urinating.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) A Swedish epidemiological study found that patients on methadone- or buprenorphine-based medication-assisted treatment (MAT) who also received benzodiazepines or other CNS depressants (for example, medications used to treat insomnia) had an increased risk of death. Among MAT-prescribed patients (aged 18 to 50), the researchers compared the risk of fatal overdose, non-overdose related mortality, and all-cause mortality during periods when CNS depressants were prescribed versus periods without CNS depressant therapy, over the interval from July 1, 2005 to December 31, 2012. The findings showed an increased risk of all-cause mortality (adjusted hazard ratio (HR) 1.44; 95% CI, 0.93 to 2.23) and non-overdose related mortality (HR 1.74; 95% CI 1.00 to 3.01) with MAT and benzodiazepine treatment; however, these data were not deemed statistically significant. Although the results indicated an increased risk of fatal overdose, non-overdose mortality, and all-cause mortality during periods of coadministration of MAT and non-benzodiazepines, only the fatal overdose and all-cause mortality data reached statistical significance; HR 2.34 (95% CI, 1.37 to 3.99) and HR 1.33 (95% CI, 1.12 to 2.45), respectively. The authors did not compare the benzodiazepine cohort with the non-benzodiazepine cohort because they did not adjust for the indication of use for the drugs 2.
b) In a study based on aggregate nationwide death certificate data from 2010 to 2014, 3495 drug overdose deaths were reported in 2014. Methadone and other CNS depressants were commonly identified as contributors in those deaths. Concurrent alprazolam use appeared in 18.1% of cases, followed by oxycodone (10.1%), cocaine (9.6%), heroin (9%), and diazepam (6.6%). The FDA reported 322 drug overdose deaths in 2014 that involved buprenorphine. Among these 322 deaths, 32.9% involved alprazolam, 17.4% involved clonazepam, 11.2% involved diazepam, 11.2% involved heroin, and 9.9% involved fentanyl. The absolute number of methadone-involved deaths was 10 times the number of buprenorphine-involved deaths, though confounding factors and differences in drug utilization were not taken into account. Whether the risk of overdose death with concurrent CNS depressant drugs differed between buprenorphine and methadone is not known 2.
Common questions
Can I take Buprenorphine and Quetiapine together?
Buprenorphine and quetiapine together add up to greater risks of slowed breathing, deep sedation, heart-rhythm changes, and gut slowdown; keep taking both as prescribed but have your care team review the combination and consider having naloxone on hand. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Buprenorphine and Quetiapine 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 Buprenorphine and Quetiapine interaction managed?
The safest approach is often to avoid using both together, but this must be decided with your prescriber, never by stopping a medicine yourself. Keep taking both as prescribed until your care team advises otherwise. Your team may lower a dose, taper one medicine, or monitor you more closely, sometimes with an ECG to check your heart rhythm. Ask whether an alternative for anxiety or sleep might be… Management is individual — always follow your own care team's guidance.
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 Buprenorphine or Quetiapine 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: SUBUTEX(R) sublingual tablets, buprenorphine sublingual tablets. Indivior Inc (per FDA), North Chesterfield, VA, 2021. DailyMed
- US Food and Drug Administration (FDA): Drug Safety Communications: FDA urges caution about withholding opioid addiction medications from patients taking benzodiazepines or CNS depressants: careful medication management can reduce risks. US Food and Drug Administration (FDA). Silver Spring, MD. 2017.
Keep reading about Buprenorphine
Keep reading about Quetiapine
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