Hydrochlorothiazide/Lisinopril and Losartan Interaction

Understanding the Hydrochlorothiazide/Lisinopril and Losartan Interaction

FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Hydrochlorothiazide/Lisinopril belongs to the Thiazide Diuretic / ACE Inhibitor Combination class and Losartan belongs to the Angiotensin II Receptor Blocker (ARB) class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Combining these two drugs can cause your potassium levels to rise and may lead to serious kidney problems without providing extra benefits. 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/Lisinopril has 13 total documented interactions on file in this dataset, and Losartan has 10. 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 will likely avoid this combination or monitor your kidney function and blood levels very 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/Lisinopril or Losartan based on a web page, speak with your prescriber or pharmacist before making any change.