Drug interactions
Diamorphine + Mirtazapine
Severity: Major
Diamorphine 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
Diamorphine (heroin) combined with mirtazapine increases the risk of excessive sedation and respiratory depression. Impaired alertness and falls are also more likely.
What this interaction means in plain words
Diamorphine 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 from opioid agonism and mirtazapine sedation.
What to do
Titrate the opioid carefully and monitor sedation and respiratory rate, especially during initiation. Counsel to avoid alcohol and other depressants.
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 Diamorphine with Mirtazapine?
MediHelp rates the interaction as major. Diamorphine 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. Diamorphine (heroin) combined with mirtazapine increases the risk of excessive sedation and respiratory depression. Impaired alertness and falls are also more likely.
How serious is the interaction between Diamorphine 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: Titrate the opioid carefully and monitor sedation and respiratory rate, especially during initiation. Counsel to avoid alcohol and other depressants.
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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