Ifosfamide and Nevirapine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Nevirapine
Ifosfamide
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased neurotoxic and nephrotoxic effects
Interaction Deep Dive
Ifosfamide is a substrate for CYP3A4 and CYP2B61, and nevirapine is an inducer of CYP3A and CYP2B6 2. Concomitant administration of ifosfamide and CYP3A4 inducers may increase the metabolism of ifosfamide to its active alkylating metabolites and may increase the formation of a neurotoxic and nephrotoxic metabolite. Patients taking ifosfamide and CYP3A4 inducers, such as nevirapine, should be carefully monitored for toxicity, and ifosfamide dose adjustment may be required 1.
Why it happens (mechanism)
Induction of cytochrome P450 3A4-mediated metabolism of ifosfamide
Common questions
Can I take Ifosfamide and Nevirapine together?
Increased neurotoxic and nephrotoxic effects Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ifosfamide and Nevirapine interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Ifosfamide or Nevirapine need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Product Information: IFEX(TM) intravenous injection, ifosfamide intravenous injection. Baxter Healthcare Corporation (per FDA), Deerfield, IL, 2012. DailyMed
- Product Information: Viramune(R) XR(TM) oral extended-release tablets, nevirapine oral extended-release tablets. Boehringer Ingelheim Pharmaceuticals, Inc (per FDA), Ridgefield, CT, 2011. DailyMed
Keep reading about Nevirapine
Keep reading about Ifosfamide
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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