Drug interactions
Fentanyl + Grapefruit
Severity: Moderate
Fentanyl and Grapefruit: 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
Grapefruit contains compounds that inhibit intestinal CYP3A4 and may raise fentanyl exposure, mainly with oral or transmucosal products. This may increase sedation and respiratory depression.
What this interaction means in plain words
Fentanyl and Grapefruit 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
Furanocoumarins in grapefruit inhibit intestinal CYP3A4, reducing first-pass metabolism of fentanyl.
What to do
Advise patients to avoid grapefruit and its juice while using fentanyl. Monitor for sedation and respiratory depression if intake occurs.
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 Fentanyl
- Alvimopan + Fentanyl Contraindicated
- Fentanyl + Isocarboxazid Contraindicated
- Fentanyl + Olanzapine / samidorphan Contraindicated
- Fentanyl + Phenelzine Contraindicated
- Fentanyl + Tranylcypromine Contraindicated
- Alfentanil + Fentanyl Major
Frequently asked questions
Can I take Fentanyl with Grapefruit?
MediHelp rates the interaction as moderate. Fentanyl and Grapefruit 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. Grapefruit contains compounds that inhibit intestinal CYP3A4 and may raise fentanyl exposure, mainly with oral or transmucosal products. This may increase sedation and respiratory depression.
How serious is the interaction between Fentanyl and Grapefruit?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise patients to avoid grapefruit and its juice while using fentanyl. Monitor for sedation and respiratory depression if intake occurs.
What other medicines interact with Fentanyl?
MediHelp also lists interactions of Fentanyl with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Fentanyl page.
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