Drug interactions
Ketoconazole + Trastuzumab emtansine
Severity: Major
Ketoconazole and Trastuzumab emtansine: 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
Ketoconazole may raise exposure to DM1, the cytotoxic component released from trastuzumab emtansine. This can increase toxicities such as hepatotoxicity, thrombocytopenia and neuropathy.
What this interaction means in plain words
Ketoconazole and Trastuzumab emtansine 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.
Ketoconazole belongs to Anti Fungals; Trastuzumab emtansine belongs to Oncology.
Why it happens
Strong CYP3A4 inhibition reduces metabolism of DM1.
What to do
Avoid strong CYP3A4 inhibitors and use an alternative if possible. If unavoidable, consider delaying the infusion until the inhibitor has cleared and monitor closely for adverse effects.
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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Other interactions of Trastuzumab emtansine
Other interactions of Ketoconazole
- Alfuzosin + Ketoconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Avanafil + Ketoconazole Contraindicated
- Conivaptan + Ketoconazole Contraindicated
- Dihydroergotamine intranasal + Ketoconazole Contraindicated
- Dihydroergotamine + Ketoconazole Contraindicated
Frequently asked questions
Can I take Ketoconazole with Trastuzumab emtansine?
MediHelp rates the interaction as major. Ketoconazole and Trastuzumab emtansine 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. Ketoconazole may raise exposure to DM1, the cytotoxic component released from trastuzumab emtansine. This can increase toxicities such as hepatotoxicity, thrombocytopenia and neuropathy.
How serious is the interaction between Ketoconazole and Trastuzumab emtansine?
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 strong CYP3A4 inhibitors and use an alternative if possible. If unavoidable, consider delaying the infusion until the inhibitor has cleared and monitor closely for adverse effects.
What other medicines interact with Trastuzumab emtansine?
MediHelp also lists interactions of Trastuzumab emtansine with, for example, Clarithromycin, Itraconazole, Ritonavir. The full list is on the Trastuzumab emtansine page.
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