Drug interactions
Cimetidine + Zaleplon
Severity: Moderate
Cimetidine and Zaleplon: 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 substantially increases zaleplon exposure because it inhibits both aldehyde oxidase and CYP3A4, the two main routes of zaleplon clearance. This can cause excess sedation, next-day impairment and psychomotor effects.
What this interaction means in plain words
Cimetidine and Zaleplon 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; Zaleplon belongs to Central Nervous System.
Why it happens
Cimetidine inhibits aldehyde oxidase and CYP3A4, decreasing the metabolism of zaleplon.
What to do
Start zaleplon at 5 mg when given with cimetidine. Alternatively use a different H2 blocker such as famotidine.
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 Zaleplon
- Calcium / magnesium / potassium / sodium oxybates + Zaleplon Contraindicated
- Sodium oxybate + Zaleplon Contraindicated
- Brexanolone + Zaleplon Major
- Buprenorphine long-acting + Zaleplon Major
- Buprenorphine subdermal implant + Zaleplon Major
- Buprenorphine transdermal + Zaleplon Major
Frequently asked questions
Can I take Cimetidine with Zaleplon?
MediHelp rates the interaction as moderate. Cimetidine and Zaleplon 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 substantially increases zaleplon exposure because it inhibits both aldehyde oxidase and CYP3A4, the two main routes of zaleplon clearance. This can cause excess sedation, next-day impairment and psychomotor effects.
How serious is the interaction between Cimetidine and Zaleplon?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Start zaleplon at 5 mg when given with cimetidine. Alternatively use a different H2 blocker such as famotidine.
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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