Drug interactions
Chlorthalidone + Spironolactone
Severity: Moderate
Chlorthalidone and Spironolactone: 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
Spironolactone retains potassium while chlorthalidone depletes it, and the combination is commonly used for hypertension and edema to balance potassium. Net potassium can still shift in either direction, and additive diuresis may cause volume depletion or hyponatremia.
What this interaction means in plain words
Chlorthalidone and Spironolactone 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.
Chlorthalidone belongs to Cardiovascular; Spironolactone belongs to Cardiovascular.
Why it happens
Aldosterone antagonism reducing potassium excretion versus thiazide-like increased distal sodium delivery and potassium loss; additive natriuresis.
What to do
Monitor serum potassium, sodium and renal function after initiation and dose changes. Avoid routine potassium supplements.
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 Spironolactone
- Amiloride + Spironolactone Contraindicated
- Eplerenone + Spironolactone Contraindicated
- Spironolactone + Triamterene Contraindicated
- Abiraterone + Spironolactone Major
- Aceclofenac + Spironolactone Major
- Acemetacin + Spironolactone Major
Frequently asked questions
Can I take Chlorthalidone with Spironolactone?
MediHelp rates the interaction as moderate. Chlorthalidone and Spironolactone 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. Spironolactone retains potassium while chlorthalidone depletes it, and the combination is commonly used for hypertension and edema to balance potassium. Net potassium can still shift in either direction, and additive diuresis may cause volume depletion or hyponatremia.
How serious is the interaction between Chlorthalidone and Spironolactone?
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 potassium, sodium and renal function after initiation and dose changes. Avoid routine potassium supplements.
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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