Drug interactions
Ifosfamide + Ketoconazole
Severity: Moderate
Ifosfamide and Ketoconazole: 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
Ifosfamide is a prodrug activated by CYP3A4 and other CYP enzymes, but is also converted to neurotoxic chloroacetaldehyde via CYP3A4. Ketoconazole may reduce formation of the active alkylating metabolites and may alter toxicity, so the effect on efficacy and neurotoxicity is unpredictable.
What this interaction means in plain words
Ifosfamide and Ketoconazole 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.
Ifosfamide belongs to Oncology; Ketoconazole belongs to Anti Fungals.
Why it happens
Ketoconazole inhibits CYP3A4-mediated bioactivation and N-dechloroethylation of ifosfamide.
What to do
Avoid the combination where possible, or monitor for reduced antitumor response and for CNS toxicity. Consider a non-azole antifungal if antifungal therapy is needed.
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 Ketoconazole
- Alfuzosin + Ketoconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Avanafil + Ketoconazole Contraindicated
- Conivaptan + Ketoconazole Contraindicated
- Dihydroergotamine intranasal + Ketoconazole Contraindicated
- Dihydroergotamine + Ketoconazole Contraindicated
Other interactions of Ifosfamide
- Adenovirus types 4 and 7 live + Ifosfamide Contraindicated
- Ifosfamide + Measles mumps and rubella vaccine Contraindicated
- Ifosfamide + Measles mumps and rubella vaccine live Contraindicated
- Ifosfamide + Measles mumps rubella and varicella vaccine live Contraindicated
- Ifosfamide + Measles vaccine Contraindicated
- Ifosfamide + Rotavirus oral vaccine live Contraindicated
Frequently asked questions
Can I take Ifosfamide with Ketoconazole?
MediHelp rates the interaction as moderate. Ifosfamide and Ketoconazole 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. Ifosfamide is a prodrug activated by CYP3A4 and other CYP enzymes, but is also converted to neurotoxic chloroacetaldehyde via CYP3A4. Ketoconazole may reduce formation of the active alkylating metabolites and may alter toxicity, so the effect on efficacy and neurotoxicity is unpredictable.
How serious is the interaction between Ifosfamide and Ketoconazole?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible, or monitor for reduced antitumor response and for CNS toxicity. Consider a non-azole antifungal if antifungal therapy is needed.
What other medicines interact with Ketoconazole?
MediHelp also lists interactions of Ketoconazole with, for example, Alfuzosin, Alprazolam, Avanafil. The full list is on the Ketoconazole page.
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