Drug interactions
Lapatinib + Topiramate
Severity: Minor
Lapatinib and Topiramate: minor 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
Lapatinib is a CYP3A4 substrate, and topiramate has weak inducing activity that might reduce lapatinib levels and antitumour effect. The magnitude is expected to be much smaller than with strong inducers.
What this interaction means in plain words
Lapatinib and Topiramate have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Lapatinib belongs to Oncology; Topiramate belongs to Central Nervous System.
Why it happens
Weak, dose-dependent CYP3A4 induction by topiramate may increase lapatinib clearance.
What to do
No empirical dose change is needed; monitor oncologic response and tolerability, and prefer a non-inducing anticonvulsant if a strong inducer would otherwise be considered.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Lapatinib and Topiramate, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Topiramate
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 Lapatinib with Topiramate?
MediHelp rates the interaction as minor. Lapatinib and Topiramate have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Lapatinib is a CYP3A4 substrate, and topiramate has weak inducing activity that might reduce lapatinib levels and antitumour effect. The magnitude is expected to be much smaller than with strong inducers.
How serious is the interaction between Lapatinib and Topiramate?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No empirical dose change is needed; monitor oncologic response and tolerability, and prefer a non-inducing anticonvulsant if a strong inducer would otherwise be considered.
What other medicines interact with Topiramate?
MediHelp also lists interactions of Topiramate with, for example, Benzhydrocodone / acetaminophen, Buprenorphine long-acting, Buprenorphine subdermal implant. The full list is on the Topiramate page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
