Drug interactions
Enzalutamide + Tolvaptan
Severity: Major
Enzalutamide and Tolvaptan: 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
Enzalutamide lowers tolvaptan plasma levels through CYP3A4 induction. Reduced exposure can lead to inadequate aquaretic effect and poor correction of hyponatremia or slower control of the underlying condition.
What this interaction means in plain words
Enzalutamide 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.
Enzalutamide belongs to Endocrine; Tolvaptan belongs to Endocrine.
Why it happens
Strong CYP3A4 induction increases the hepatic and intestinal metabolism of tolvaptan.
What to do
Avoid concomitant use of tolvaptan with strong CYP3A4 inducers. If it must be given, monitor serum sodium or clinical response and adjust the tolvaptan dose accordingly.
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 Enzalutamide
- Doravirine + Enzalutamide Contraindicated
- Elbasvir / grazoprevir + Enzalutamide Contraindicated
- Ensitrelvir + Enzalutamide Contraindicated
- Enzalutamide + Fostemsavir Contraindicated
- Enzalutamide + Isavuconazonium Contraindicated
- Enzalutamide + Lenacapavir Contraindicated
Other interactions of Tolvaptan
- Atazanavir + Tolvaptan Contraindicated
- Ceritinib + Tolvaptan Contraindicated
- Cobicistat + Tolvaptan Contraindicated
- Conivaptan + Tolvaptan Contraindicated
- Darunavir + Tolvaptan Contraindicated
- Idelalisib + Tolvaptan Contraindicated
Frequently asked questions
Can I take Enzalutamide with Tolvaptan?
MediHelp rates the interaction as major. Enzalutamide 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. Enzalutamide lowers tolvaptan plasma levels through CYP3A4 induction. Reduced exposure can lead to inadequate aquaretic effect and poor correction of hyponatremia or slower control of the underlying condition.
How serious is the interaction between Enzalutamide 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: Avoid concomitant use of tolvaptan with strong CYP3A4 inducers. If it must be given, monitor serum sodium or clinical response and adjust the tolvaptan dose accordingly.
What other medicines interact with Enzalutamide?
MediHelp also lists interactions of Enzalutamide with, for example, Doravirine, Elbasvir / grazoprevir, Ensitrelvir. The full list is on the Enzalutamide page.
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