Drug interactions
Mirtazapine + Ritonavir
Severity: Moderate
Mirtazapine and Ritonavir: 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
Ritonavir inhibits CYP3A4 and may raise mirtazapine concentrations, increasing sedation and other adverse effects. Ritonavir may also have some effects on cardiac conduction.
What this interaction means in plain words
Mirtazapine and Ritonavir 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 belongs to Central Nervous System; Ritonavir belongs to Anti Virals.
Why it happens
Inhibition of CYP3A4-mediated mirtazapine metabolism.
What to do
Monitor for excess sedation, weight gain and cardiac effects, and lower the mirtazapine dose if adverse effects appear. Consider ECG monitoring in at-risk patients.
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 Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Frequently asked questions
Can I take Mirtazapine with Ritonavir?
MediHelp rates the interaction as moderate. Mirtazapine and Ritonavir 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. Ritonavir inhibits CYP3A4 and may raise mirtazapine concentrations, increasing sedation and other adverse effects. Ritonavir may also have some effects on cardiac conduction.
How serious is the interaction between Mirtazapine and Ritonavir?
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 for excess sedation, weight gain and cardiac effects, and lower the mirtazapine dose if adverse effects appear. Consider ECG monitoring in at-risk patients.
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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