Drug interactions
Elvitegravir / cobicistat / emtricitabine / tenofovir df + Ifosfamide
Severity: Major
Elvitegravir / cobicistat / emtricitabine / tenofovir df and Ifosfamide: major 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 CYP2B6 and also converted to a neurotoxic chloroacetaldehyde metabolite by CYP3A4. Cobicistat inhibits CYP3A4, which can change the balance between active and toxic metabolites and alter efficacy and toxicity. The clinical impact is not well characterised.
What this interaction means in plain words
Elvitegravir / cobicistat / emtricitabine / tenofovir df and Ifosfamide can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Cobicistat inhibits CYP3A4, altering the metabolic activation and toxic-metabolite formation of ifosfamide.
What to do
If possible, use an antiretroviral regimen without a pharmacokinetic booster during ifosfamide cycles. If the combination is unavoidable, monitor closely for neurotoxicity, nephrotoxicity, myelosuppression and reduced antitumour response.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Elvitegravir / cobicistat / emtricitabine / tenofovir df and Ifosfamide, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
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 Elvitegravir / cobicistat / emtricitabine / tenofovir df with Ifosfamide?
MediHelp rates the interaction as major. Elvitegravir / cobicistat / emtricitabine / tenofovir df and Ifosfamide can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Ifosfamide is a prodrug activated by CYP3A4 and CYP2B6 and also converted to a neurotoxic chloroacetaldehyde metabolite by CYP3A4. Cobicistat inhibits CYP3A4, which can change the balance between active and toxic metabolites and alter efficacy and toxicity. The clinical impact is not well characterised.
How serious is the interaction between Elvitegravir / cobicistat / emtricitabine / tenofovir df and Ifosfamide?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: If possible, use an antiretroviral regimen without a pharmacokinetic booster during ifosfamide cycles. If the combination is unavoidable, monitor closely for neurotoxicity, nephrotoxicity, myelosuppression and reduced antitumour response.
What other medicines interact with Ifosfamide?
MediHelp also lists interactions of Ifosfamide with, for example, Adenovirus types 4 and 7 live, Measles mumps and rubella vaccine, Measles mumps and rubella vaccine live. The full list is on the Ifosfamide page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
