Drug interactions
Mitotane + Tolvaptan
Severity: Major
Mitotane and Tolvaptan: major interaction.
Last updated Sources: US FDA label
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
Mitotane is a potent CYP3A4 inducer and can substantially reduce tolvaptan concentrations, since tolvaptan is a CYP3A4 substrate. This may lead to loss of the aquaretic effect and inadequate sodium correction, and the induction can persist for weeks after mitotane is stopped.
What this interaction means in plain words
Mitotane and Tolvaptan 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.
Mitotane belongs to Oncology; Tolvaptan belongs to Endocrine.
Why it happens
Induction of CYP3A4 by mitotane increases the metabolism of tolvaptan.
What to do
Monitor serum sodium and clinical response and consider increasing the tolvaptan dose, or use an alternative therapy. Continue monitoring after mitotane discontinuation as induction wanes.
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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References
Other interactions of Tolvaptan
- Atazanavir + Tolvaptan Contraindicated
- Ceritinib + Tolvaptan Contraindicated
- Cobicistat + Tolvaptan Contraindicated
- Conivaptan + Tolvaptan Contraindicated
- Darunavir + Tolvaptan Contraindicated
- Idelalisib + Tolvaptan Contraindicated
Other interactions of Mitotane
- Doravirine + Mitotane Contraindicated
- Fostemsavir + Mitotane Contraindicated
- Lorlatinib + Mitotane Contraindicated
- Abiraterone + Mitotane Major
- Apixaban + Mitotane Major
- Aprepitant + Mitotane Major
Frequently asked questions
Can I take Mitotane with Tolvaptan?
MediHelp rates the interaction as major. Mitotane and Tolvaptan 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. Mitotane is a potent CYP3A4 inducer and can substantially reduce tolvaptan concentrations, since tolvaptan is a CYP3A4 substrate. This may lead to loss of the aquaretic effect and inadequate sodium correction, and the induction can persist for weeks after mitotane is stopped.
How serious is the interaction between Mitotane and Tolvaptan?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor serum sodium and clinical response and consider increasing the tolvaptan dose, or use an alternative therapy. Continue monitoring after mitotane discontinuation as induction wanes.
What other medicines interact with Tolvaptan?
MediHelp also lists interactions of Tolvaptan with, for example, Atazanavir, Ceritinib, Cobicistat. The full list is on the Tolvaptan page.
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