Drug interactions
Buprenorphine long-acting + Clozapine
Severity: Major
Buprenorphine long-acting and Clozapine: major interaction.
Last updated Sources: UK SmPC
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Clozapine and buprenorphine can each prolong the QT interval, so combining them may increase the risk of serious arrhythmia. Buprenorphine also adds to sedation and respiratory depression. A long-acting injection cannot be withdrawn quickly if problems develop.
What this interaction means in plain words
Buprenorphine long-acting and Clozapine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Additive effects on cardiac repolarisation, plus additive CNS depression.
What to do
Obtain a baseline ECG before starting and repeat it if other QT-prolonging drugs are added. Correct potassium and magnesium, and monitor for sedation and respiratory depression.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Clozapine
- Clozapine + Deferiprone Contraindicated
- Clozapine + Irinotecan Contraindicated
- Clozapine + Pimozide Contraindicated
- Clozapine + Thioridazine Contraindicated
- Acalabrutinib + Clozapine Major
- Adagrasib + Clozapine Major
Frequently asked questions
Can I take Buprenorphine long-acting with Clozapine?
MediHelp rates the interaction as major. Buprenorphine long-acting and Clozapine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Clozapine and buprenorphine can each prolong the QT interval, so combining them may increase the risk of serious arrhythmia. Buprenorphine also adds to sedation and respiratory depression. A long-acting injection cannot be withdrawn quickly if problems develop.
How serious is the interaction between Buprenorphine long-acting and Clozapine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG before starting and repeat it if other QT-prolonging drugs are added. Correct potassium and magnesium, and monitor for sedation and respiratory depression.
What other medicines interact with Clozapine?
MediHelp also lists interactions of Clozapine with, for example, Deferiprone, Irinotecan, Pimozide. The full list is on the Clozapine page.
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