Moricizine 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
Buprenorphine
Moricizine
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.
Buprenorphine (used for pain or opioid treatment) and moricizine (a heart rhythm medicine) can affect your body in ways that add up when taken together. Both can stretch out your heart's electrical cycle (called the QT interval), which can lead to a dangerous, irregular heartbeat. Buprenorphine can also slow your breathing and make you very sleepy, and combining medicines that affect the heart or nervous system raises that risk.
This doesn't mean you can't be treated safely. Your care team can watch your heart, adjust doses, and make a plan that fits you. Please don't stop either medicine on your own, just talk with your pharmacist or doctor about the safest way forward.
Effect: Additive QT prolongation plus additive CNS/respiratory depression. Neither drug is a prodrug; this is a pharmacodynamic (not metabolic) interaction, so both effects are additive.
- Direction: Increased combined risk of torsades-type arrhythmia and of sedation/respiratory depression.
- Severity/evidence: Major; mechanism probable. Onset unspecified.
- Management: Avoid concomitant use of buprenorphine with QT-prolonging agents where possible. If unavoidable, obtain baseline and follow-up ECGs, correct electrolytes (K+, Mg2+), use the lowest effective doses, and monitor for sedation and respiratory compromise. Strongly consider prescribing naloxone. Do not withhold medication-assisted treatment solely due to this interaction.
What happens
An increased risk of QT interval prolongation and an increased risk of CNS and respiratory depression
Interaction Deep Dive
Concurrent administration of buprenorphine with agents capable of prolonging the QT interval should be avoided. Combining these medications also heightens the likelihood of respiratory depression, deep sedation, coma, and death. Discontinuing benzodiazepines or other CNS depressants is favored rather than using them together. For certain patients, either observation within a higher level of care or a taper may be suitable. For others, it may be appropriate to gradually withdraw a patient from a prescribed benzodiazepine or other CNS depressant, or to reduce it to the lowest effective dose. When simultaneous use cannot be avoided, monitor and handle the situation carefully; weigh the use of alternative treatments for anxiety or insomnia and give strong consideration to prescribing naloxone for the emergency management of opioid overdose2. A Swedish epidemiological study found that patients undergoing methadone- or buprenorphine-based medication-assisted treatment (MAT) together with benzodiazepines or other CNS depressants (for example, medications used for insomnia) face an elevated risk of death. Based on an analysis of aggregate nationwide death certificate data spanning 2010 to 2014, most overdose deaths involving buprenorphine and methadone also involved concurrent CNS depressant use. Whether the risk of overdose death associated with concurrent CNS depressant drugs varied between buprenorphine and methadone remains unknown 3.
Why it happens (mechanism)
Additive QT interval prolongation; additive CNS depression
How to manage this interaction
What your care team may do:
- Decide whether both drugs are truly needed, or whether an alternative for either purpose is safer.
- Check your heart rhythm with an ECG and review your electrolyte levels.
- Use the lowest effective doses and monitor you more closely for excess drowsiness or slowed breathing. Doses may be adjusted and individualized by your team.
- Possibly prescribe naloxone for emergency use.
What you should do: Keep taking both exactly as prescribed unless told otherwise. Tell your pharmacist or prescriber about all your medicines, and get help right away for fainting, palpitations, severe drowsiness, or trouble breathing.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
3 reports — tap to read
a) A Swedish epidemiological study reported that patients undergoing methadone- or buprenorphine-based medication-assisted treatment (MAT) together with benzodiazepines or other CNS depressants (for example, drugs used to treat insomnia) have an increased risk of death. From July 1, 2005 through December 31, 2012, investigators analyzed the risk of fatal overdose, non-overdose related mortality, and all-cause mortality during periods when CNS depressants were prescribed compared with periods without CNS depressant therapy in MAT-prescribed patients (aged 18 to 50). The findings showed an elevated 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 combined MAT and benzodiazepine treatment; however, these data were not deemed statistically significant. Although the results showed an elevated risk of fatal overdose, non-overdose mortality, and all-cause mortality during periods of coadministration of MAT and non-benzodiazepines, only the data for fatal overdose and all-cause mortality were regarded as statistically significant; 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 perform a comparison between the benzodiazepine cohort and the non-benzodiazepine cohort because they did not adjust for the indication for which the drugs were used 3.
b) According to a study of aggregate nationwide death certificate data spanning 2010 to 2014, 3495 drug overdose deaths were reported in 2014. Methadone and other CNS depressants were often cited as contributors to those deaths. Concurrent ALPRAZolam use was reported 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. Of those 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 greater than 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 unknown 3.
c) Thorough QT studies of buprenorphine products have shown modest QT prolongation equal to 15 msec or less 1.
Common questions
Can I take Moricizine and Buprenorphine together?
Together, buprenorphine and moricizine raise the risk of a dangerous heart rhythm and of dangerous sedation or slowed breathing, so avoid combining them when possible and have your care team monitor you closely (ECG, doses) if you must use both. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Moricizine 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 Moricizine and Buprenorphine interaction managed?
What your care team may do: Decide whether both drugs are truly needed, or whether an alternative for either purpose is safer. Check your heart rhythm with an ECG and review your electrolyte levels. Use the lowest effective doses and monitor you more closely for excess drowsiness or slowed breathing. Doses may be adjusted and individualized by your team. Possibly prescribe naloxone for emergency u… 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 Moricizine 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: 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 Moricizine
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