Drug interactions
Citalopram + Ritonavir
Severity: Moderate
Citalopram 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 raise citalopram levels and can itself affect QT, increasing the risk of QT prolongation. Serotonergic toxicity has also been reported with ritonavir and SSRIs.
What this interaction means in plain words
Citalopram 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.
Citalopram belongs to Central Nervous System; Ritonavir belongs to Anti Virals.
Why it happens
Ritonavir inhibits CYP3A4 (and affects other pathways), increasing citalopram exposure, with additive QT effects.
What to do
Use the lowest effective citalopram dose and monitor ECG in at-risk patients. Watch for agitation, tremor, hyperthermia and other signs of 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 Citalopram
- Cisapride + Citalopram Contraindicated
- Citalopram + Dronedarone Contraindicated
- Citalopram + Escitalopram Contraindicated
- Citalopram + Isocarboxazid Contraindicated
- Citalopram + Methylene blue Contraindicated
- Citalopram + Phenelzine 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 Citalopram with Ritonavir?
MediHelp rates the interaction as moderate. Citalopram 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 raise citalopram levels and can itself affect QT, increasing the risk of QT prolongation. Serotonergic toxicity has also been reported with ritonavir and SSRIs.
How serious is the interaction between Citalopram 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: Use the lowest effective citalopram dose and monitor ECG in at-risk patients. Watch for agitation, tremor, hyperthermia and other signs of serotonin toxicity.
What other medicines interact with Citalopram?
MediHelp also lists interactions of Citalopram with, for example, Cisapride, Dronedarone, Escitalopram. The full list is on the Citalopram page.
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