Edema due to increased hydrostatic pressure may be a result of serious cardiopulmonary disease (which reduces glomerular perfusion in the kidney) or to kidney injury or disease (which may reduce glomerular excretion of salt and water by the kidney) or due to relatively benign conditions such as menstrual-related fluid retention, or as an adverse effect of dihydropyridine calcium channel blockers, which commonly cause swelling of the feet and lower legs. Edema due to decreased oncotic pressure may be a result of leaking of blood proteins through the glomeruli of an injured kidney or a result of diminished synthesis of blood proteins by a damaged liver. Regardless of cause, chlortalidone may reduce the severity of edema by reducing intravascular volume and thereby reducing intravascular hydrostatic pressure. Bone fracture prevention
Chlortalidone decreases mineral bone loss by promoting calcium retention by the kidney, and by directly stimulating osteoblast differentiation and bone mineral formation. A Cochrane review found tentative evidence that thiazide exposure was associated with a reduced risk of hip fracture. A secondary analysis of data from the ALLHAT study found that chlortalidone reduced risk of hip and pelvis fracture. Kidney stone prevention
Chlortalidone reduces the amount of calcium excreted in urine, reducing the risk of calcium oxalate kidney stones. In people who have had multiple episodes of calcium oxalate kidney stones, chlortalidone lowers the risk of having another episode of kidney stones. Chlortalidone is more effective than hydrochlorothiazide for lowering urine calcium levels and is therefore probably more effective.
Some recommend chlortalidone over hydrochlorothiazide. A meta-analysis of randomized controlled trials found that chlortalidone is more effective than hydrochlorothiazide for lowering blood pressure, while the two drugs have similar toxicity.Trials of chlortalidone for high blood pressure found that lower doses of chlortalidone (e.g., 12.5 mg daily in ALLHAT study) had maximal blood pressure lowering effect and that higher doses did not lower it more. Chlortalidone and other thiazide diuretics are effective for lowering high blood pressure in persons with chronic kidney disease, although the risk of adverse effects is higher in these persons. Left ventricular hypertrophy
Chlortalidone is used to treat left ventricular hypertrophy in the heart; it works chiefly by lowering blood pressure, and thereby reducing systemic vascular resistance. There is evidence that chlortalidone is superior to hydrochlorothiazide for reducing the mass of the left ventricle of the heart in persons with enlargement of the left ventricle of the heart. Chlortalidone is superior to angiotensin converting enzyme Inhibitors or angiotensin II receptor blockers for inducing regression of enlargement of the left ventricle, which is the main pumping chamber of the heart. Swelling
Chlortalidone reduces edema (swelling) by increasing urinary salt and water excretion, lowering intravascular hydrostatic pressure and thereby lowering transcapillary pressure (see Starling Equation). Edema may be caused by either increased hydrostatic pressure or reduced oncotic pressure in the blood vessels.