Drug interactions
Olanzapine + Ritonavir
Severity: Moderate
Olanzapine 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 may lower olanzapine concentrations, possibly reducing its antipsychotic effect. Ritonavir induces olanzapine metabolism despite being a CYP3A4 inhibitor.
What this interaction means in plain words
Olanzapine 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.
Olanzapine belongs to Central Nervous System; Ritonavir belongs to Anti Virals.
Why it happens
Ritonavir induces CYP1A2 and glucuronidation, increasing olanzapine clearance.
What to do
Monitor clinical response and consider increasing the olanzapine dose if symptoms recur. Reassess dose if ritonavir is stopped.
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 Olanzapine
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 Olanzapine with Ritonavir?
MediHelp rates the interaction as moderate. Olanzapine 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 may lower olanzapine concentrations, possibly reducing its antipsychotic effect. Ritonavir induces olanzapine metabolism despite being a CYP3A4 inhibitor.
How serious is the interaction between Olanzapine 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 clinical response and consider increasing the olanzapine dose if symptoms recur. Reassess dose if ritonavir is stopped.
What other medicines interact with Olanzapine?
MediHelp also lists interactions of Olanzapine with, for example, Amisulpride, Amoxapine, Apomorphine. The full list is on the Olanzapine page.
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