Drug interactions
Deflazacort + Tucatinib
Severity: Major
Deflazacort and Tucatinib: 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
Tucatinib inhibits CYP3A4 and can raise exposure to the active metabolite of deflazacort. This increases the risk of corticosteroid adverse effects such as Cushingoid features, hyperglycemia, immunosuppression and adrenal suppression.
What this interaction means in plain words
Deflazacort and Tucatinib 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.
Deflazacort belongs to Miscellaneous; Tucatinib belongs to Oncology.
Why it happens
Inhibition of CYP3A4 by tucatinib decreases clearance of deflazacort's active metabolite.
What to do
Avoid the combination where possible. If it cannot be avoided, reduce the deflazacort dose as per labeling for CYP3A4 inhibitors and monitor for corticosteroid toxicity.
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 Deflazacort
- Adenovirus types 4 and 7 live + Deflazacort Contraindicated
- Bcg vaccine live + Deflazacort Contraindicated
- Deflazacort + Influenza virus vaccine quadrivalent intranasal Contraindicated
- Deflazacort + Measles mumps and rubella vaccine Contraindicated
- Deflazacort + Measles mumps and rubella vaccine live Contraindicated
- Deflazacort + Measles mumps rubella and varicella vaccine live Contraindicated
Other interactions of Tucatinib
- Cisapride + Tucatinib Contraindicated
- Eletriptan + Tucatinib Contraindicated
- Ergotamine + Tucatinib Contraindicated
- Flibanserin + Tucatinib Contraindicated
- Ranolazine + Tucatinib Contraindicated
- Amobarbital + Tucatinib Major
Frequently asked questions
Can I take Deflazacort with Tucatinib?
MediHelp rates the interaction as major. Deflazacort and Tucatinib 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. Tucatinib inhibits CYP3A4 and can raise exposure to the active metabolite of deflazacort. This increases the risk of corticosteroid adverse effects such as Cushingoid features, hyperglycemia, immunosuppression and adrenal suppression.
How serious is the interaction between Deflazacort and Tucatinib?
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 the combination where possible. If it cannot be avoided, reduce the deflazacort dose as per labeling for CYP3A4 inhibitors and monitor for corticosteroid toxicity.
What other medicines interact with Deflazacort?
MediHelp also lists interactions of Deflazacort with, for example, Adenovirus types 4 and 7 live, Bcg vaccine live, Influenza virus vaccine quadrivalent intranasal. The full list is on the Deflazacort page.
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