Drug interactions
Methyclothiazide + Tolvaptan
Severity: Moderate
Methyclothiazide 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
Thiazide diuretics lower serum potassium and sodium while tolvaptan raises serum sodium and may raise potassium. Combined diuresis can also worsen volume depletion, and rapid sodium correction is a concern.
What this interaction means in plain words
Methyclothiazide 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.
Why it happens
Additive diuretic and fluid-losing effects with opposing effects on potassium; thiazide-induced hyponatremia is corrected by aquaresis.
What to do
Monitor serum sodium closely to avoid overly rapid correction, together with potassium and volume status. Adjust the doses of either drug based on laboratory results.
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
Frequently asked questions
Can I take Methyclothiazide with Tolvaptan?
MediHelp rates the interaction as moderate. Methyclothiazide 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. Thiazide diuretics lower serum potassium and sodium while tolvaptan raises serum sodium and may raise potassium. Combined diuresis can also worsen volume depletion, and rapid sodium correction is a concern.
How serious is the interaction between Methyclothiazide 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 closely to avoid overly rapid correction, together with potassium and volume status. Adjust the doses of either drug based on laboratory results.
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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