Drug interactions
Imatinib + Phenobarbital
Severity: Major
Imatinib and Phenobarbital: 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
Phenobarbital is a strong inducer of CYP3A4, which is the main route of imatinib clearance. Imatinib concentrations may drop substantially and reduce its efficacy. The effect is clinically important in cancer treatment.
What this interaction means in plain words
Imatinib and Phenobarbital 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
Phenobarbital induces CYP3A4 and possibly P-glycoprotein, increasing imatinib clearance.
What to do
Avoid the combination when possible and choose a non-enzyme-inducing anticonvulsant. If it cannot be avoided, increase the imatinib dose with close response monitoring.
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 Imatinib
- Imatinib + Lomitapide Contraindicated
- Imatinib + Lonafarnib Contraindicated
- Amobarbital + Imatinib Major
- Apalutamide + Imatinib Major
- Avapritinib + Imatinib Major
- Benzhydrocodone / acetaminophen + Imatinib Major
Frequently asked questions
Can I take Imatinib with Phenobarbital?
MediHelp rates the interaction as major. Imatinib and Phenobarbital 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. Phenobarbital is a strong inducer of CYP3A4, which is the main route of imatinib clearance. Imatinib concentrations may drop substantially and reduce its efficacy. The effect is clinically important in cancer treatment.
How serious is the interaction between Imatinib and Phenobarbital?
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 when possible and choose a non-enzyme-inducing anticonvulsant. If it cannot be avoided, increase the imatinib dose with close response monitoring.
What other medicines interact with Imatinib?
MediHelp also lists interactions of Imatinib with, for example, Lomitapide, Lonafarnib, Amobarbital. The full list is on the Imatinib page.
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