Conivaptan and Apixaban: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Aug 8, 2026 · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Conivaptan
Apixaban
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
These two medicines can clash. Apixaban (Eliquis) is a blood thinner. Your body clears it partly with a liver enzyme called CYP3A. Conivaptan (Vaprisol) blocks that enzyme, so apixaban can build up in your body. More apixaban means a higher chance of bleeding, such as easy bruising, nosebleeds, or bleeding that is hard to stop.
This concern is based mainly on how the drugs work, not on many real-world reports, but it is taken seriously because bleeding can be dangerous. The good news is your care team can manage this by adjusting your plan or spacing out the medicines. Please check with your pharmacist or doctor before changing anything.
Effect: Conivaptan (strong CYP3A inhibitor) may increase apixaban exposure. Apixaban is partly eliminated via CYP3A4; it is an active drug, not a prodrug, so inhibition raises AUC/Cmax and increases bleeding risk.
- Direction: Increased apixaban exposure and anticoagulant effect.
- Magnitude: Not quantified for apixaban; conivaptan raised AUC of midazolam, simvastatin, amlodipine.
- Onset: Unspecified.
- Evidence: Theoretical.
- Management: Avoid concurrent use. Do not initiate the CYP3A substrate sooner than 1 week after completing conivaptan. Monitor for bleeding.
What happens
Increased CYP3A substrate exposure
Interaction Deep Dive
The combined use of conivaptan, a potent CYP3A inhibitor, with medications that are cleared mainly through CYP3A-mediated metabolism should be avoided, since the exposure of the CYP3A substrate can rise as a consequence. The AUC of the CYP3A substrates midazolam, simvastatin, and amLODIPine was raised by conivaptan. Initiation of the CYP3A substrate should not occur any earlier than 1 week following the end of conivaptan therapy1.
Why it happens (mechanism)
Inhibition of CYP3A-mediated substrate metabolism by conivaptan
How to manage this interaction
What your care team may do:
- Generally avoid using conivaptan and apixaban together, since combining them can raise apixaban levels.
- If you recently finished conivaptan, your team may wait at least 1 week before starting a CYP3A drug like apixaban.
- Watch you more closely for signs of bleeding.
What you should do: Keep taking both exactly as prescribed unless your prescriber tells you otherwise. Tell your pharmacist or doctor that you may be on both, and report unusual bruising, blood in urine or stool, or bleeding that will not stop.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
3 reports — tap to read
a) When administered as an intravenous dose of 40 mg/day, the potent CYP3A inhibitor conivaptan raised the AUC of midazolam, a CYP3A substrate, by roughly 100% following a 1 mg IV dose and by 200% following a 2 mg oral dose 1.
b) At an intravenous dose of 30 mg/day, conivaptan produced a threefold increase in the AUC of simvastatin, a CYP3A substrate 1.
c) Conivaptan given orally at 40 mg twice daily doubled both the AUC and the half-life of amLODIPine, a CYP3A substrate 1.
Common questions
Can I take Conivaptan and Apixaban together?
Conivaptan can raise apixaban levels and bleeding risk, so these are usually avoided together; wait at least a week after conivaptan before starting apixaban, and ask your care team before changing anything. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Conivaptan and Apixaban interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Conivaptan and Apixaban interaction managed?
What your care team may do: Generally avoid using conivaptan and apixaban together, since combining them can raise apixaban levels. If you recently finished conivaptan, your team may wait at least 1 week before starting a CYP3A drug like apixaban. Watch you more closely for signs of bleeding. What you should do: Keep taking both exactly as prescribed unless your prescriber tells you otherwise. Tel… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Conivaptan or Apixaban need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: VAPRISOL(R) intravenous injection, conivaptan HCl intravenous injection. Cumberland Pharmaceuticals Inc. (per manufacturer), Nashville, TN, 2014.
Keep reading about Conivaptan
Keep reading about Apixaban
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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