Drug interactions
Cimetidine + Indinavir
Severity: Moderate
Cimetidine and Indinavir: moderate 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
Cimetidine may raise indinavir levels through CYP3A4 inhibition, while the higher gastric pH may reduce indinavir absorption. The net effect is unpredictable and could cause toxicity such as nephrolithiasis or reduced antiviral efficacy.
What this interaction means in plain words
Cimetidine and Indinavir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Cimetidine inhibits CYP3A4 and raises gastric pH, with indinavir absorption depending on acidity.
What to do
Maintain hydration and monitor for renal toxicity and virologic response, or use an alternative acid suppressant strategy. Consider therapeutic drug monitoring when available.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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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
Frequently asked questions
Can I take Cimetidine with Indinavir?
MediHelp rates the interaction as moderate. Cimetidine and Indinavir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Cimetidine may raise indinavir levels through CYP3A4 inhibition, while the higher gastric pH may reduce indinavir absorption. The net effect is unpredictable and could cause toxicity such as nephrolithiasis or reduced antiviral efficacy.
How serious is the interaction between Cimetidine and Indinavir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Maintain hydration and monitor for renal toxicity and virologic response, or use an alternative acid suppressant strategy. Consider therapeutic drug monitoring when available.
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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