Drug interactions
Griseofulvin + Lapatinib
Severity: Major
Griseofulvin and Lapatinib: 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
Griseofulvin may considerably lower lapatinib exposure, which could compromise anticancer efficacy. Lapatinib is a CYP3A4 substrate whose levels fall markedly with inducers.
What this interaction means in plain words
Griseofulvin and Lapatinib 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.
Griseofulvin belongs to Anti Fungals; Lapatinib belongs to Oncology.
Why it happens
Griseofulvin-mediated CYP3A4 induction increases lapatinib clearance.
What to do
Prefer a non-inducing antifungal. If unavoidable, lapatinib dose escalation as per labeling for strong inducers should be considered with close monitoring of response and 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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Other interactions of Griseofulvin
Other interactions of Lapatinib
- Dofetilide + Lapatinib Contraindicated
- Ibutilide + Lapatinib Contraindicated
- Lapatinib + Pimozide Contraindicated
- Lapatinib + Saquinavir Contraindicated
- Lapatinib + Thioridazine Contraindicated
- Adagrasib + Lapatinib Major
Frequently asked questions
Can I take Griseofulvin with Lapatinib?
MediHelp rates the interaction as major. Griseofulvin and Lapatinib 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. Griseofulvin may considerably lower lapatinib exposure, which could compromise anticancer efficacy. Lapatinib is a CYP3A4 substrate whose levels fall markedly with inducers.
How serious is the interaction between Griseofulvin and Lapatinib?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer a non-inducing antifungal. If unavoidable, lapatinib dose escalation as per labeling for strong inducers should be considered with close monitoring of response and toxicity.
What other medicines interact with Griseofulvin?
MediHelp also lists interactions of Griseofulvin with, for example, Cyclosporine, Cyclosporin, Desogestrel-ethinyl estradiol. The full list is on the Griseofulvin page.
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