Drug interactions
Cimetidine + Roflumilast
Severity: Moderate
Cimetidine and Roflumilast: 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 inhibits several CYP enzymes including CYP1A2 and CYP3A4, both involved in roflumilast metabolism. Exposure to roflumilast and its active N-oxide metabolite may rise, increasing adverse effects such as diarrhea, nausea, weight loss, headache and insomnia.
What this interaction means in plain words
Cimetidine and Roflumilast 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 belongs to Gastrointestinal Tract; Roflumilast belongs to Respiratory.
Why it happens
Cimetidine inhibits CYP1A2 and CYP3A4, reducing roflumilast clearance.
What to do
Monitor for roflumilast adverse effects such as weight loss, GI upset, insomnia and psychiatric symptoms. Consider an alternative acid suppressant such as a proton pump inhibitor or famotidine if tolerability is poor.
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 Roflumilast
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 Roflumilast?
MediHelp rates the interaction as moderate. Cimetidine and Roflumilast 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 inhibits several CYP enzymes including CYP1A2 and CYP3A4, both involved in roflumilast metabolism. Exposure to roflumilast and its active N-oxide metabolite may rise, increasing adverse effects such as diarrhea, nausea, weight loss, headache and insomnia.
How serious is the interaction between Cimetidine and Roflumilast?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for roflumilast adverse effects such as weight loss, GI upset, insomnia and psychiatric symptoms. Consider an alternative acid suppressant such as a proton pump inhibitor or famotidine if tolerability is poor.
What other medicines interact with Roflumilast?
MediHelp also lists interactions of Roflumilast with, for example, Apalutamide, Carbamazepine, Efavirenz. The full list is on the Roflumilast page.
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