Drug interactions
Chlorothiazide + Tolvaptan
Severity: Moderate
Chlorothiazide and Tolvaptan: 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
Thiazides lower potassium and sodium, whereas tolvaptan raises sodium and can raise potassium. Combined use may lead to unpredictable electrolyte shifts and, with excess aquaresis, volume depletion.
What this interaction means in plain words
Chlorothiazide and Tolvaptan 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.
Chlorothiazide belongs to Cardiovascular; Tolvaptan belongs to Endocrine.
Why it happens
Pharmacodynamic: thiazide-induced natriuresis and potassium loss combined with tolvaptan aquaresis and potassium-raising effect.
What to do
Monitor serum sodium, potassium and volume status frequently, especially at initiation. Adjust either drug if sodium rises too rapidly or electrolytes become abnormal.
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?
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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 Chlorothiazide
Frequently asked questions
Can I take Chlorothiazide with Tolvaptan?
MediHelp rates the interaction as moderate. Chlorothiazide and Tolvaptan 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. Thiazides lower potassium and sodium, whereas tolvaptan raises sodium and can raise potassium. Combined use may lead to unpredictable electrolyte shifts and, with excess aquaresis, volume depletion.
How serious is the interaction between Chlorothiazide and Tolvaptan?
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, potassium and volume status frequently, especially at initiation. Adjust either drug if sodium rises too rapidly or electrolytes become abnormal.
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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