Drug interactions
Fentanyl + Ketamine
Severity: Moderate
Fentanyl and Ketamine: 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
Ketamine and fentanyl are often used together for analgesia and anesthesia, and the combination increases sedation, hypotension and respiratory depression. Dissociative effects and opioid-related ventilatory depression can add up.
What this interaction means in plain words
Fentanyl and Ketamine 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.
Fentanyl belongs to Musculoskeletal; Ketamine belongs to Central Nervous System.
Why it happens
Additive CNS depression through opioid receptor agonism and NMDA receptor antagonism.
What to do
Use in monitored settings with doses titrated to effect and reduced as needed. Monitor respiratory rate, oxygen saturation and blood pressure.
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
Other interactions of Ketamine
Frequently asked questions
Can I take Fentanyl with Ketamine?
MediHelp rates the interaction as moderate. Fentanyl and Ketamine 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. Ketamine and fentanyl are often used together for analgesia and anesthesia, and the combination increases sedation, hypotension and respiratory depression. Dissociative effects and opioid-related ventilatory depression can add up.
How serious is the interaction between Fentanyl and Ketamine?
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 in monitored settings with doses titrated to effect and reduced as needed. Monitor respiratory rate, oxygen saturation and blood pressure.
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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