Drug interactions
Cyclophosphamide + Nelfinavir
Severity: Moderate
Cyclophosphamide and Nelfinavir: 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
Nelfinavir inhibits CYP3A4 and may alter how cyclophosphamide is converted to active and inactive metabolites. The direction of the net clinical effect is uncertain.
What this interaction means in plain words
Cyclophosphamide and Nelfinavir 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 belongs to Oncology; Nelfinavir belongs to Anti Virals.
Why it happens
CYP3A4 inhibition by nelfinavir may modify cyclophosphamide metabolism.
What to do
Monitor blood counts and for signs of cyclophosphamide toxicity or reduced efficacy. Consider an alternative antiretroviral if feasible.
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 Nelfinavir
- Alfuzosin + Nelfinavir Contraindicated
- Avanafil + Nelfinavir Contraindicated
- Dronedarone + Nelfinavir Contraindicated
- Eletriptan + Nelfinavir Contraindicated
- Ergotamine + Nelfinavir Contraindicated
- Flibanserin + Nelfinavir Contraindicated
Frequently asked questions
Can I take Cyclophosphamide with Nelfinavir?
MediHelp rates the interaction as moderate. Cyclophosphamide and Nelfinavir 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. Nelfinavir inhibits CYP3A4 and may alter how cyclophosphamide is converted to active and inactive metabolites. The direction of the net clinical effect is uncertain.
How serious is the interaction between Cyclophosphamide and Nelfinavir?
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 blood counts and for signs of cyclophosphamide toxicity or reduced efficacy. Consider an alternative antiretroviral if feasible.
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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