Drug interactions
Itraconazole + Thiotepa
Severity: Major
Itraconazole and Thiotepa: major interaction.
Last updated Sources: US FDA label
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
Itraconazole inhibits CYP3A4, which converts thiotepa to its active metabolite. Altered exposure to parent drug and metabolite may change efficacy and toxicity, including myelosuppression.
What this interaction means in plain words
Itraconazole and Thiotepa 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.
Itraconazole belongs to Anti Fungals; Thiotepa belongs to Oncology.
Why it happens
Strong CYP3A4 inhibition by itraconazole alters thiotepa biotransformation to TEPA.
What to do
Avoid combining where possible and use a non-inhibiting antifungal. If unavoidable, monitor closely for adverse reactions and blood counts.
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?
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References
Other interactions of Thiotepa
- Bendamustine + Thiotepa Major
- Chlorambucil + Thiotepa Major
- Clarithromycin + Thiotepa Major
- Cyclophosphamide + Thiotepa Major
- Dacarbazine + Thiotepa Major
- Deferiprone + Thiotepa Major
Other interactions of Itraconazole
- Alfuzosin + Itraconazole Contraindicated
- Alprazolam + Itraconazole Contraindicated
- Avanafil + Itraconazole Contraindicated
- Conivaptan + Itraconazole Contraindicated
- Dihydroergotamine intranasal + Itraconazole Contraindicated
- Dihydroergotamine + Itraconazole Contraindicated
Frequently asked questions
Can I take Itraconazole with Thiotepa?
MediHelp rates the interaction as major. Itraconazole and Thiotepa 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. Itraconazole inhibits CYP3A4, which converts thiotepa to its active metabolite. Altered exposure to parent drug and metabolite may change efficacy and toxicity, including myelosuppression.
How serious is the interaction between Itraconazole and Thiotepa?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid combining where possible and use a non-inhibiting antifungal. If unavoidable, monitor closely for adverse reactions and blood counts.
What other medicines interact with Thiotepa?
MediHelp also lists interactions of Thiotepa with, for example, Bendamustine, Chlorambucil, Clarithromycin. The full list is on the Thiotepa page.
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