Drug interactions
Hydrochlorothiazide + Tolvaptan
Severity: Moderate
Hydrochlorothiazide 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
Both drugs promote fluid loss, so combined use can lead to excessive volume depletion, hypotension and renal impairment. Tolvaptan raises serum sodium and the effect on potassium is variable, so electrolytes can shift unpredictably.
What this interaction means in plain words
Hydrochlorothiazide 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.
Hydrochlorothiazide belongs to Cardiovascular; Tolvaptan belongs to Endocrine.
Why it happens
Tolvaptan causes aquaresis via vasopressin V2 receptor blockade while thiazides cause natriuresis, producing additive volume depletion.
What to do
Monitor serum sodium, potassium, volume status and renal function closely, particularly at tolvaptan initiation. Avoid overly rapid sodium correction.
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 Hydrochlorothiazide
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 Hydrochlorothiazide with Tolvaptan?
MediHelp rates the interaction as moderate. Hydrochlorothiazide 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. Both drugs promote fluid loss, so combined use can lead to excessive volume depletion, hypotension and renal impairment. Tolvaptan raises serum sodium and the effect on potassium is variable, so electrolytes can shift unpredictably.
How serious is the interaction between Hydrochlorothiazide 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, volume status and renal function closely, particularly at tolvaptan initiation. Avoid overly rapid sodium correction.
What other medicines interact with Hydrochlorothiazide?
MediHelp also lists interactions of Hydrochlorothiazide with, for example, Dofetilide, Amifostine, Amiodarone. The full list is on the Hydrochlorothiazide page.
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