Drug interactions
Conivaptan + Fentanyl
Severity: Major
Conivaptan and Fentanyl: major 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
Conivaptan is a CYP3A4 inhibitor and may increase fentanyl exposure, leading to enhanced sedation and respiratory depression. Its short-term intravenous use limits duration but the risk is real during treatment.
What this interaction means in plain words
Conivaptan and Fentanyl can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Inhibition of CYP3A4 reduces fentanyl metabolism.
What to do
Avoid if feasible; if used, lower fentanyl dose and monitor for respiratory depression and sedation during and after conivaptan infusion.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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 Conivaptan with Fentanyl?
MediHelp rates the interaction as major. Conivaptan and Fentanyl can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Conivaptan is a CYP3A4 inhibitor and may increase fentanyl exposure, leading to enhanced sedation and respiratory depression. Its short-term intravenous use limits duration but the risk is real during treatment.
How serious is the interaction between Conivaptan and Fentanyl?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid if feasible; if used, lower fentanyl dose and monitor for respiratory depression and sedation during and after conivaptan infusion.
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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