Diuretics
The water pills
High blood pressure and fluid overload from heart, liver or kidney conditions.
Makes the kidneys send more sodium — and the water that follows it — into the urine.
The 6 diuretics in the PTCB Top 200
| Generic | Brand | Common use |
|---|---|---|
| Hydrochlorothiazide | Microzide | hypertension, edema |
| Furosemide | Lasix | edema, HF |
| Spironolactone | Aldactone | HF, edema, ↑aldosterone |
| Hydrochlorothiazide / Triamterene | Dyazide / Maxzide | hypertension, edema |
| Chlorthalidone | Hygroton / Thalitone | hypertension, edema |
| Torsemide | Demadex | edema, HF |
Tap any generic name for its full drug guide — brand↔generic, side effects, interactions and the exam tip.
What to know for the exam
- check_circleLoop diuretics are the strongest; thiazides are the usual first choice for blood pressure.
- check_circleLoops and thiazides lower potassium; spironolactone and triamterene raise it.
- check_circleUsually taken in the morning so the trips to the bathroom aren't overnight.
- check_circleHydrochlorothiazide appears inside many combination blood-pressure products.
Potassium is the thing to watch. A potassium-sparing diuretic taken with a potassium supplement or an ACE inhibitor can push levels too high.
Know which direction each subgroup moves potassium — that distinction is what the class is usually tested on.
Drill diuretics the way the PTCE asks them
RxReflex groups the Top 200 drugs into classes like this one, then quizzes you on brand↔generic, class, side effects and interactions. Plus a guided Learn path, pharmacy math and 40+ cheat sheets. Free to start.
Frequently asked
What drugs are in the diuretics class? add
Hydrochlorothiazide, Furosemide, Spironolactone, Hydrochlorothiazide / Triamterene, Chlorthalidone, Torsemide. All are in the PTCB Top 200.
What are diuretics used for? add
High blood pressure and fluid overload from heart, liver or kidney conditions.
How do diuretics work? add
Makes the kidneys send more sodium — and the water that follows it — into the urine.
Last reviewed August 7, 2026. For education only — not medical advice. Not affiliated with or endorsed by the PTCB.