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Chlorthalidone Dosage

Applies to the following strength(s): 50 mg ; 25 mg ; 100 mg ; 15 mg

The information at is not a substitute for medical advice. Always consult your doctor or pharmacist.

Usual Adult Dose for:

Additional dosage information:

Usual Adult Dose for Edema

Initial dose: 50-100 mg orally once a day.
Maintenance dose: 25-100 mg once a day or
50-200 mg every other day.

Usual Adult Dose for Hypertension

Initial dose: 25 mg orally once a day (15 mg for Thalitone).
Maintenance dose: 25-100 mg once a day (15-50 mg for Thalitone).

Renal Dose Adjustments

Chlorthalidone is not expected to be filtered into the renal tubule (its site of action) when the glomerular filtration rate is less than 10 mL/min.

Liver Dose Adjustments

Data not available

Dose Adjustments

Dosage adjustments are recommended to be made no more frequently than weekly. Patients with liver disease or renal dysfunction should have dosage adjustments made cautiously.


Chlorthalidone is contraindicated in patients with anuria.

Chlorthalidone therapy should be used with caution in severe renal disease. In patients with renal disease, chlorthalidone or related drugs may precipitate azotemia. Cumulative effects may develop in patients with impaired renal function. If progressive renal impairment becomes evident, as indicated by a rising nonprotein nitrogen or blood urea nitrogen, a careful reappraisal of the treatment is necessary with consideration given to withholding or discontinuing diuretic therapy.

Chlorthalidone therapy should be used with caution in patients with impaired hepatic function or progressive liver disease, since minor alterations of fluid and electrolyte balance may precipitate hepatic coma.

Sensitivity reactions may be observed in patients with a history of allergy or bronchial asthma.

The possibility of exacerbation or activation of systemic lupus erythematosus has been observed with thiazide diuretics, which are structurally related to chlorthalidone. However, systemic lupus erythematosus has not been observed following chlorthalidone administration.

Hypokalemia may develop with chlorthalidone as with any other diuretic, especially with brisk diuresis when severe cirrhosis is present. Interference with adequate oral electrolyte intake will also contribute to hypokalemia.

Any chloride deficit is generally mild and usually does not require specific therapy except under extraordinary circumstances (as in liver disease or renal disease). Dilutional hyponatremia may be observed in edematous patients in hot weather, appropriate therapy is water restriction, rather than administration of salt except in rare instances when the hyponatremia is life threatening. In actual salt depletion, appropriate replacement is the treatment of choice.

Hyperuricemia may occur or frank gout may be precipitated in certain patients receiving chlorthalidone therapy. Thiazide-like diuretics have been shown to increase the urinary excretion of magnesium, which may result in hypomagnesemia.

The antihypertensive effects chlorthalidone may be enhanced in the post-sympathectomy patient.

Calcium excretion is decreased by thiazide-like agents. Pathological changes in the parathyroid gland with hypercalcemia and hypophosphatemia have been reported in few patients on thiazide therapy. The common complications of hyperparathyroidism such as renal lithiasis, bone resorption and peptic ulceration have not been observed.

Periodic determination of serum electrolytes to detect possible electrolyte imbalance should be conducted at appropriate intervals.

Electrolyte abnormalities (i.e., hypokalemia, hyponatremia) and glucose intolerance may occur during chlorthalidone therapy.

Safety and effectiveness have not been established in pediatric patients (less than 18 years of age).


Data not available

Other Comments

The maximum daily dose for hypertension is 100 mg (50 mg for Thalitone).

The maximum daily dose for edema is 200 mg (120 mg for Thalitone).

Periodic monitoring of electrolytes is recommended, particularly in elderly patients and in patients receiving a high dose.