Drug interactions
Cimetidine + Neratinib
Severity: Major
Cimetidine and Neratinib: 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
Neratinib solubility falls as pH rises, and H2 antagonists reduce its absorption. This may reduce efficacy in breast cancer treatment.
What this interaction means in plain words
Cimetidine and Neratinib 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.
Cimetidine belongs to Gastrointestinal Tract; Neratinib belongs to Oncology.
Why it happens
Cimetidine raises gastric pH, decreasing neratinib dissolution and absorption.
What to do
Avoid H2 antagonists if possible; if needed, take neratinib at least 2 hours before the next H2 antagonist dose and at least 10 hours after the previous one.
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 Cimetidine
- Cimetidine + Dofetilide Contraindicated
- Cimetidine + Fezolinetant Contraindicated
- Alfentanil + Cimetidine Major
- Atazanavir + Cimetidine Major
- Carmustine + Cimetidine Major
- Cimetidine + Citalopram Major
Other interactions of Neratinib
- Amiodarone + Neratinib Major
- Amobarbital + Neratinib Major
- Aprepitant + Neratinib Major
- Armodafinil + Neratinib Major
- Bosentan + Neratinib Major
- Carbamazepine + Neratinib Major
Frequently asked questions
Can I take Cimetidine with Neratinib?
MediHelp rates the interaction as major. Cimetidine and Neratinib 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. Neratinib solubility falls as pH rises, and H2 antagonists reduce its absorption. This may reduce efficacy in breast cancer treatment.
How serious is the interaction between Cimetidine and Neratinib?
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 H2 antagonists if possible; if needed, take neratinib at least 2 hours before the next H2 antagonist dose and at least 10 hours after the previous one.
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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