Drug interactions
Cimetidine + Levorphanol
Severity: Moderate
Cimetidine and Levorphanol: 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 hepatic oxidative metabolism and can raise exposure to some opioids. Levorphanol is mainly glucuronidated, so the effect is less certain, but additive opioid effects such as sedation and respiratory depression are possible.
What this interaction means in plain words
Cimetidine and Levorphanol 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 inhibition of hepatic CYP enzymes may reduce opioid clearance; levorphanol is mainly cleared by glucuronidation so the effect is uncertain.
What to do
Monitor for sedation and respiratory depression when starting or stopping cimetidine, and reduce the levorphanol dose if excess effect occurs. Consider famotidine as an alternative.
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 Levorphanol?
MediHelp rates the interaction as moderate. Cimetidine and Levorphanol 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 hepatic oxidative metabolism and can raise exposure to some opioids. Levorphanol is mainly glucuronidated, so the effect is less certain, but additive opioid effects such as sedation and respiratory depression are possible.
How serious is the interaction between Cimetidine and Levorphanol?
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 sedation and respiratory depression when starting or stopping cimetidine, and reduce the levorphanol dose if excess effect occurs. Consider famotidine as an alternative.
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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