Drug interactions
Cobicistat + Tolvaptan
Severity: Contraindicated
Cobicistat and Tolvaptan: contraindicated 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
Cobicistat is a potent CYP3A inhibitor used as a pharmacokinetic booster and is expected to greatly raise tolvaptan levels. This risks excessive water loss, dehydration, and too rapid correction of hyponatremia.
What this interaction means in plain words
Cobicistat and Tolvaptan are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Cobicistat belongs to Miscellaneous; Tolvaptan belongs to Endocrine.
Why it happens
Potent mechanism-based CYP3A4 inhibition decreases tolvaptan clearance.
What to do
Do not combine; choose a non-boosted regimen or hold tolvaptan. Monitor serum sodium if exposure cannot be avoided.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Tolvaptan
- Atazanavir + Tolvaptan Contraindicated
- Ceritinib + Tolvaptan Contraindicated
- Conivaptan + Tolvaptan Contraindicated
- Darunavir + Tolvaptan Contraindicated
- Idelalisib + Tolvaptan Contraindicated
- Indinavir + Tolvaptan Contraindicated
Other interactions of Cobicistat
- Alfuzosin + Cobicistat Contraindicated
- Apalutamide + Cobicistat Contraindicated
- Cobicistat + Colchicine Contraindicated
- Cobicistat + Dronedarone Contraindicated
- Cobicistat + Eletriptan Contraindicated
- Cobicistat + Eplerenone Contraindicated
Frequently asked questions
Can I take Cobicistat with Tolvaptan?
MediHelp rates the interaction as contraindicated. Cobicistat and Tolvaptan are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Cobicistat is a potent CYP3A inhibitor used as a pharmacokinetic booster and is expected to greatly raise tolvaptan levels. This risks excessive water loss, dehydration, and too rapid correction of hyponatremia.
How serious is the interaction between Cobicistat and Tolvaptan?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not combine; choose a non-boosted regimen or hold tolvaptan. Monitor serum sodium if exposure cannot be avoided.
What other medicines interact with Tolvaptan?
MediHelp also lists interactions of Tolvaptan with, for example, Atazanavir, Ceritinib, Conivaptan. The full list is on the Tolvaptan page.
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