Drug interactions
Chlorothiazide + Chlorthalidone
Severity: Moderate
Chlorothiazide and Chlorthalidone: 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 are thiazide-type diuretics, so combined use duplicates therapy and increases risk of hypokalemia, hyponatremia, dehydration and hypotension.
What this interaction means in plain words
Chlorothiazide and Chlorthalidone 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; Chlorthalidone belongs to Cardiovascular.
Why it happens
Additive inhibition of the distal tubule sodium-chloride cotransporter with increased potassium and sodium loss.
What to do
Avoid concurrent use of two thiazide-type diuretics unless deliberate, and monitor electrolytes and renal function.
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 Chlorthalidone
Other interactions of Chlorothiazide
Frequently asked questions
Can I take Chlorothiazide with Chlorthalidone?
MediHelp rates the interaction as moderate. Chlorothiazide and Chlorthalidone 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 are thiazide-type diuretics, so combined use duplicates therapy and increases risk of hypokalemia, hyponatremia, dehydration and hypotension.
How serious is the interaction between Chlorothiazide and Chlorthalidone?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concurrent use of two thiazide-type diuretics unless deliberate, and monitor electrolytes and renal function.
What other medicines interact with Chlorthalidone?
MediHelp also lists interactions of Chlorthalidone with, for example, Amifostine, Atenolol-chlorthalidone, Candesartan-hydrochlorothiazide. The full list is on the Chlorthalidone page.
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