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Hydrochlorothiazide/Triamterene and Spironolactone Interaction

Drug interaction information between Hydrochlorothiazide/Triamterene and Spironolactone.

Hydrochlorothiazide/Triamterene and Spironolactone have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Hydrochlorothiazide/Triamterene and Spironolactone. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.

Drug A

Hydrochlorothiazide/Triamterene

Thiazide / Potassium-Sparing Diuretic Combination

Drug B

Spironolactone

Potassium-Sparing Diuretic / Aldosterone Antagonist

How They Interact

Both drugs stop the kidneys from getting rid of potassium. This can cause potassium to build up to unsafe levels in your blood.

What To Do

Your doctor should monitor your blood potassium levels closely. You may need to avoid this combination or have your doses adjusted.

FDA Label Information

Use of lisinopril with potassium-sparing diuretics (e.g., spironolactone, eplerenone, triamterene, or amiloride), potassium supplements, or potassium-containing salt substitutes may lead to significant increases in serum potassium.

Spironolactone Also Interacts With

View all Spironolactone interactions →

Frequently Asked Questions

Can I take Hydrochlorothiazide/Triamterene and Spironolactone together?

This is a minor interaction. Your doctor should monitor your blood potassium levels closely. You may need to avoid this combination or have your doses adjusted.

How serious is the interaction between Hydrochlorothiazide/Triamterene and Spironolactone?

This interaction is classified as "minor" severity by the FDA. Minor interactions are unlikely to cause significant problems but should still be mentioned to your healthcare provider.

Why do Hydrochlorothiazide/Triamterene and Spironolactone interact?

Both drugs stop the kidneys from getting rid of potassium. This can cause potassium to build up to unsafe levels in your blood.

Understanding the Hydrochlorothiazide/Triamterene and Spironolactone Interaction

FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Hydrochlorothiazide/Triamterene belongs to the Thiazide / Potassium-Sparing Diuretic Combination class and Spironolactone belongs to the Potassium-Sparing Diuretic / Aldosterone Antagonist class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Both drugs stop the kidneys from getting rid of potassium. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.

Context around a specific patient determines real-world impact. Hydrochlorothiazide/Triamterene has 13 total documented interactions on file in this dataset, and Spironolactone has 23. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Your doctor should monitor your blood potassium levels closely. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.

An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Hydrochlorothiazide/Triamterene or Spironolactone based on a web page, speak with your prescriber or pharmacist before making any change.

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.