Drug interactions
Lithium + Mirtazapine
Severity: Moderate
Lithium 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
Both drugs have been associated with QT changes, and lithium toxicity can cause ECG abnormalities and arrhythmias. Mirtazapine is also sometimes combined with lithium for augmentation, and serotonergic effects are possible.
What this interaction means in plain words
Lithium 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.
Lithium belongs to Central Nervous System; Mirtazapine belongs to Central Nervous System.
Why it happens
Additive QT effects; lithium also has serotonergic activity that may add to mirtazapine.
What to do
Monitor serum lithium levels, renal function and electrolytes. Obtain an ECG if the patient has cardiac disease or other QT-prolonging drugs, and watch for serotonin toxicity.
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 Mirtazapine
- Isocarboxazid + Mirtazapine Contraindicated
- Mirtazapine + Phenelzine Contraindicated
- Mirtazapine + Pimozide Contraindicated
- Mirtazapine + Procarbazine Contraindicated
- Mirtazapine + Rasagiline Contraindicated
- Mirtazapine + Selegiline Contraindicated
Other interactions of Lithium
- Lithium + Thioridazine Contraindicated
- Lithium + Vandetanib Contraindicated
- Aceclofenac + Lithium Major
- Acemetacin + Lithium Major
- Amisulpride + Lithium Major
- Amlodipine-benazepril + Lithium Major
Frequently asked questions
Can I take Lithium with Mirtazapine?
MediHelp rates the interaction as moderate. Lithium 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. Both drugs have been associated with QT changes, and lithium toxicity can cause ECG abnormalities and arrhythmias. Mirtazapine is also sometimes combined with lithium for augmentation, and serotonergic effects are possible.
How serious is the interaction between Lithium 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: Monitor serum lithium levels, renal function and electrolytes. Obtain an ECG if the patient has cardiac disease or other QT-prolonging drugs, and watch for serotonin toxicity.
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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