Drug interactions
Atazanavir + Cyclophosphamide
Severity: Moderate
Atazanavir and Cyclophosphamide: 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
Cyclophosphamide is a prodrug activated mainly by CYP2B6 with contributions from CYP3A4 and CYP2C9, and also undergoes CYP3A4 inactivation. Atazanavir inhibits CYP3A4 and may change the balance between active and toxic or inactive metabolites, with an uncertain net clinical effect.
What this interaction means in plain words
Atazanavir and Cyclophosphamide 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.
Atazanavir belongs to Anti Virals; Cyclophosphamide belongs to Oncology.
Why it happens
CYP3A4 inhibition by atazanavir may alter cyclophosphamide metabolism.
What to do
Monitor for myelosuppression, infection, and signs of cyclophosphamide toxicity such as hemorrhagic cystitis. Consider the interaction when dosing and check blood counts more often.
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 Cyclophosphamide
Other interactions of Atazanavir
- Alfuzosin + Atazanavir Contraindicated
- Atazanavir + Avanafil Contraindicated
- Atazanavir + Dronedarone Contraindicated
- Atazanavir + Eletriptan Contraindicated
- Atazanavir + Eplerenone Contraindicated
- Atazanavir + Ergotamine Contraindicated
Frequently asked questions
Can I take Atazanavir with Cyclophosphamide?
MediHelp rates the interaction as moderate. Atazanavir and Cyclophosphamide 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. Cyclophosphamide is a prodrug activated mainly by CYP2B6 with contributions from CYP3A4 and CYP2C9, and also undergoes CYP3A4 inactivation. Atazanavir inhibits CYP3A4 and may change the balance between active and toxic or inactive metabolites, with an uncertain net clinical effect.
How serious is the interaction between Atazanavir and Cyclophosphamide?
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 myelosuppression, infection, and signs of cyclophosphamide toxicity such as hemorrhagic cystitis. Consider the interaction when dosing and check blood counts more often.
What other medicines interact with Cyclophosphamide?
MediHelp also lists interactions of Cyclophosphamide with, for example, Adenovirus types 4 and 7 live, Belatacept, Bendamustine. The full list is on the Cyclophosphamide page.
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