Drug interactions
Fentanyl + Mirtazapine
Severity: Moderate
Fentanyl and Mirtazapine: moderate interaction.
Last updated
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
Mirtazapine is sedating and adds to the CNS depression caused by fentanyl. Serotonergic effects are also possible, although the risk is considered low.
What this interaction means in plain words
Fentanyl and Mirtazapine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Fentanyl belongs to Musculoskeletal; Mirtazapine belongs to Central Nervous System.
Why it happens
Additive CNS depression, with a possible minor serotonergic contribution.
What to do
Start with low doses and titrate carefully, and monitor for excessive sedation and respiratory depression. Watch for serotonin syndrome features such as agitation, tremor and hyperthermia.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Fentanyl
- Alvimopan + Fentanyl Contraindicated
- Fentanyl + Isocarboxazid Contraindicated
- Fentanyl + Olanzapine / samidorphan Contraindicated
- Fentanyl + Phenelzine Contraindicated
- Fentanyl + Tranylcypromine Contraindicated
- Alfentanil + Fentanyl Major
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 Fentanyl with Mirtazapine?
MediHelp rates the interaction as moderate. Fentanyl and Mirtazapine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Mirtazapine is sedating and adds to the CNS depression caused by fentanyl. Serotonergic effects are also possible, although the risk is considered low.
How serious is the interaction between Fentanyl and Mirtazapine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Start with low doses and titrate carefully, and monitor for excessive sedation and respiratory depression. Watch for serotonin syndrome features such as agitation, tremor and hyperthermia.
What other medicines interact with Fentanyl?
MediHelp also lists interactions of Fentanyl with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Fentanyl page.
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