Hydrochlorothiazide and Hydrochlorothiazide/Triamterene Interaction
Drug interaction information between Hydrochlorothiazide and Hydrochlorothiazide/Triamterene.
Hydrochlorothiazide and Hydrochlorothiazide/Triamterene have a documented major interaction in FDA labeling.
FDA drug labeling documents a major-severity interaction between Hydrochlorothiazide and Hydrochlorothiazide/Triamterene. 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.
How They Interact
Both of these medicines can cause your body to lose too much water and salt, which can lead to dehydration or electrolyte imbalances.
What To Do
Your doctor should monitor your blood pressure and salt levels closely to ensure they stay in a healthy range.
FDA Label Information
Monitor blood pressure, renal function, and electrolytes in patients on lisinopril and hydrochlorothiazide tablets and other agents that affect the RAS. Do not coadminister aliskiren with lisinopril and hydrochlorothiazide tablets in patients with diabetes. No meaningful clinically important pharmacokinetic interactions occurred when lisinopril was used concomitantly with propranolol, digoxin, or hydrochlorothiazide.
Hydrochlorothiazide Also Interacts With
- Aliskiren major
- Lisinopril major
- Olmesartan moderate
- Losartan minor
- Spironolactone minor
Hydrochlorothiazide/Triamterene Also Interacts With
- Aliskiren major
- Lisinopril minor
- Losartan minor
- Spironolactone minor
- Propranolol minor
Frequently Asked Questions
Can I take Hydrochlorothiazide and Hydrochlorothiazide/Triamterene together?
This is a major interaction. Your doctor should monitor your blood pressure and salt levels closely to ensure they stay in a healthy range.
How serious is the interaction between Hydrochlorothiazide and Hydrochlorothiazide/Triamterene?
This interaction is classified as "major" severity by the FDA. Major interactions may be life-threatening or cause serious side effects.
Why do Hydrochlorothiazide and Hydrochlorothiazide/Triamterene interact?
Both of these medicines can cause your body to lose too much water and salt, which can lead to dehydration or electrolyte imbalances.
Understanding the Hydrochlorothiazide and Hydrochlorothiazide/Triamterene Interaction
FDA-approved prescribing information for these two drugs flags their combination as a major-severity interaction. Hydrochlorothiazide belongs to the Thiazide Diuretic class and Hydrochlorothiazide/Triamterene belongs to the Thiazide / Potassium-Sparing Diuretic Combination class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Both of these medicines can cause your body to lose too much water and salt, which can lead to dehydration or electrolyte imbalances. 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 has 31 total documented interactions on file in this dataset, and Hydrochlorothiazide/Triamterene has 13. 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 pressure and salt levels closely to ensure they stay in a healthy range. 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 or Hydrochlorothiazide/Triamterene 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.
Read our methodology - how this data is sourced, computed, and verified.