Chlorthalidone is a diuretic used to treat hypertension or edema caused by heart failure, renal failure, hepatic cirrhosis, estrogen therapy, and other conditions. Chlorthalidone improves blood pressure and swelling by preventing water absorption from the kidneys through inhibition of the Na+/Cl− symporter in the distal convoluted tubule cells in the kidney.
- Mechanism
- Curator reviewed · 3 references
Chlorthalidone prevents reabsorption of sodium and chloride through inhibition of the Na+/Cl- symporter in the cortical diluting segment of the ascending limb of the loop of Henle. Reduction of sodium reabsorption subsequently reduces extracellular fluid and plasma volume via an osmotic, sodium-driven diuresis. By increasing the delivery of sodium to the distal renal tubule, Chlorthalidone indirectly increases potassium excretion via the sodium-potassium exchange mechanism. The exact mechanism of chlorthalidone's anti-hypertensive effect is under debate, however, it is thought that increased diuresis results in decreased plasma and extracellular fluid volume which therefore requires decreased cardiac output and overall lowers blood pressure. Chlorthalidone has also been shown to decrease platelet aggregation and vascular permeability, as well as promote angiogenesis in vitro, which is thought to be partly the result of reductions in carbonic anhydrase–dependent pathways. These pathways may play a role in chlorthalidone's cardiovascular risk reduction effects.
- Primary indication
- Chlorthalidone is indicated in the management of hypertension either as the sole therapeutic agent or to enhance the effect of other antihypertensive drugs in the more severe forms of hypertension.Curator reviewed · 8 structured indications
- Formula / weight
- C14H11ClN2O4S · 338.766 g/mol (avg)
- First approval
- Canada, 1997 · United States, 1981
- Also known as
- Chlorphthalidolone · Chlortalidone · Phthalamodine · Phthalamudine
- Brand names
Resolves to
JIVPVXMEBJLZRO-UHFFFAOYSA-NSMILESNS(=O)(=O)C1=C(Cl)C=CC(=C1)C1(O)NC(=O)C2=CC=CC=C12What you can answer from here — as of September 23, 2026
Which drugs share a target with Chlorthalidone, and which of those have an active Phase 3 trial?
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