Drug interactions
Cimetidine + Suvorexant
Severity: Moderate
Cimetidine and Suvorexant: 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 increase suvorexant exposure, intensifying next-day somnolence and impaired driving or alertness.
What this interaction means in plain words
Cimetidine and Suvorexant 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; Suvorexant belongs to Central Nervous System.
Why it happens
Cimetidine inhibits CYP3A4, which is the main metabolic pathway of suvorexant.
What to do
Use the lower suvorexant starting dose of 5 mg at bedtime with moderate CYP3A inhibitors and titrate cautiously. Counsel about next-day drowsiness.
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
Other interactions of Suvorexant
Frequently asked questions
Can I take Cimetidine with Suvorexant?
MediHelp rates the interaction as moderate. Cimetidine and Suvorexant 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 increase suvorexant exposure, intensifying next-day somnolence and impaired driving or alertness.
How serious is the interaction between Cimetidine and Suvorexant?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use the lower suvorexant starting dose of 5 mg at bedtime with moderate CYP3A inhibitors and titrate cautiously. Counsel about next-day drowsiness.
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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