Drug interactions
Buprenorphine long-acting + Mirtazapine
Severity: Major
Buprenorphine long-acting and Mirtazapine: 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
Long-acting injectable buprenorphine combined with mirtazapine increases sedation and the risk of respiratory depression. Additive QT prolongation is also possible, and the long duration of the injection means effects persist after dosing.
What this interaction means in plain words
Buprenorphine long-acting and Mirtazapine 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 CNS and respiratory depression and possible additive QT prolongation.
What to do
Monitor for sedation and respiratory depression, particularly after injection and when mirtazapine is started or increased. Check an ECG when other QT risk factors are present.
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 Mirtazapine
- Isocarboxazid + Mirtazapine Contraindicated
- Mirtazapine + Phenelzine Contraindicated
- Mirtazapine + Pimozide Contraindicated
- Mirtazapine + Procarbazine Contraindicated
- Mirtazapine + Rasagiline Contraindicated
- Mirtazapine + Selegiline Contraindicated
Frequently asked questions
Can I take Buprenorphine long-acting with Mirtazapine?
MediHelp rates the interaction as major. Buprenorphine long-acting and Mirtazapine 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. Long-acting injectable buprenorphine combined with mirtazapine increases sedation and the risk of respiratory depression. Additive QT prolongation is also possible, and the long duration of the injection means effects persist after dosing.
How serious is the interaction between Buprenorphine long-acting and Mirtazapine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for sedation and respiratory depression, particularly after injection and when mirtazapine is started or increased. Check an ECG when other QT risk factors are present.
What other medicines interact with Mirtazapine?
MediHelp also lists interactions of Mirtazapine with, for example, Isocarboxazid, Phenelzine, Pimozide. The full list is on the Mirtazapine page.
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