Drug interactions
Cimetidine + Tucatinib
Severity: Minor
Cimetidine and Tucatinib: 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
Tucatinib inhibits P-glycoprotein and can raise exposure to P-gp substrates. Cimetidine has a wide safety margin, so a significant effect is unlikely.
What this interaction means in plain words
Cimetidine and Tucatinib have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Cimetidine belongs to Gastrointestinal Tract; Tucatinib belongs to Oncology.
Why it happens
P-glycoprotein inhibition by tucatinib may increase cimetidine absorption.
What to do
No routine adjustment is needed; monitor for cimetidine adverse effects in vulnerable patients.
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?
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Other interactions of Cimetidine
- Cimetidine + Dofetilide Contraindicated
- Cimetidine + Fezolinetant Contraindicated
- Alfentanil + Cimetidine Major
- Atazanavir + Cimetidine Major
- Carmustine + Cimetidine Major
- Cimetidine + Citalopram Major
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 Cimetidine with Tucatinib?
MediHelp rates the interaction as minor. Cimetidine and Tucatinib have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Tucatinib inhibits P-glycoprotein and can raise exposure to P-gp substrates. Cimetidine has a wide safety margin, so a significant effect is unlikely.
How serious is the interaction between Cimetidine and Tucatinib?
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 routine adjustment is needed; monitor for cimetidine adverse effects in vulnerable patients.
What other medicines interact with Cimetidine?
MediHelp also lists interactions of Cimetidine with, for example, Dofetilide, Fezolinetant, Alfentanil. The full list is on the Cimetidine page.
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