Drug interactions
Conivaptan + Isoniazid
Severity: Moderate
Conivaptan and Isoniazid: 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
Conivaptan is a CYP3A4 substrate, and inhibition of its metabolism can raise levels and cause excessively rapid sodium correction. Isoniazid is only a weak-to-moderate CYP3A4 inhibitor, so the effect is likely modest.
What this interaction means in plain words
Conivaptan and Isoniazid 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
Inhibition of CYP3A4 metabolism of conivaptan.
What to do
Monitor serum sodium frequently and watch for overly rapid correction. Reduce or stop conivaptan if the sodium rise is too fast.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Conivaptan and Isoniazid, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Isoniazid
Frequently asked questions
Can I take Conivaptan with Isoniazid?
MediHelp rates the interaction as moderate. Conivaptan and Isoniazid 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. Conivaptan is a CYP3A4 substrate, and inhibition of its metabolism can raise levels and cause excessively rapid sodium correction. Isoniazid is only a weak-to-moderate CYP3A4 inhibitor, so the effect is likely modest.
How serious is the interaction between Conivaptan and Isoniazid?
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 serum sodium frequently and watch for overly rapid correction. Reduce or stop conivaptan if the sodium rise is too fast.
What other medicines interact with Isoniazid?
MediHelp also lists interactions of Isoniazid with, for example, Bacillus calmette-guerin substrain tice, Benzhydrocodone / acetaminophen, Carbamazepine. The full list is on the Isoniazid page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
