Hydrochlorothiazide Dosage

Usual Adult Dose for Edema

25 to 100 mg orally as a single or divided dose.

Usual Adult Dose for Hypertension

Initial dose: 25 mg orally once a day.
Maintenance dose: May increase to 50 mg orally as a single or 2 divided doses.

Usual Adult Dose for Nephrocalcinosis

Initial: 25 mg orally once a day
Maintenance dose: May increase to 50 mg twice a day

Usual Adult Dose for Osteoporosis

Initial: 25 mg orally once a day
Maintenance dose: May increase to 50 mg per day

Usual Adult Dose for Diabetes Insipidus

Initial: 50 mg orally once a day
Maintenance dose: May increase to 100 mg per day

Usual Pediatric Dose for Edema

Less than 6 months: 3 mg/kg/day orally in 2 divided doses.

Greater than or equal to 6 months and less than 2 years: 1 to 3 mg/kg/day orally as a single or 2 divided doses.
Maximum dose: 37.5 mg/day

2 to 17 years: 1 to 3 mg/kg/day orally as a single or 2 divided doses.
Maximum dose: 3 mg/kg/day (50 mg/day)

Usual Pediatric Dose for Hypertension

Infants and Children:
Initial dose: 1 mg/kg/day once daily. May increase to a maximum of 37.5 mg/kg/day
Maximum dose: Do not exceed 50 mg/day

Renal Dose Adjustments

CrCl less than 25 mL/min: Not recommended.

CrCl 25 to 80 mL/min: Initial dose: 12.5 mg orally once a day.
Maintenance dose: 12.5 to 50 mg orally as a single or 2 divided doses.

Liver Dose Adjustments

Thiazides 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.

Dose Adjustments

Many patients with edema respond to intermittent therapy by giving doses on alternate days or 3 to 5 days/week. Patients usually do not require more than 50 mg/day when combined with other antihypertensives.

Precautions

Hydrochlorothiazide is contraindicated in patients with anuria.

Patients should be monitored routinely for fluid and electrolyte imbalances, especially hyponatremia, hypochloremic alkalosis, hypokalemia, and hypomagnesemia. Serum and urine electrolytes should be measured when the patient is vomiting excessively or receiving parenteral fluids.

Hypokalemia may develop with hydrochlorothiazide therapy, especially with aggressive diuresis, following prolonged therapy, and in the presence of severe cirrhosis.

Hydrochlorothiazide should be discontinued if azotemia and oliguria increase during the treatment of severe progressive renal disease.

There are reports of mild, asymptomatic hyponatremia. Rarely, patients develop severe, symptomatic hyponatremia; immediate attention and appropriate treatment is required in these cases.

Caution is recommended in patients with hepatic dysfunction or progressive hepatic disease. Thiazides can precipitate hepatic coma in patients with severe liver disease.

Hydrochlorothiazide may cause impairment of glucose tolerance resulting in the need for dosage adjustment of antidiabetic agents, including insulin, in patients with diabetes mellitus.

Increased cholesterol and triglyceride levels may occur in association with thiazide diuretic therapy.

Hyperuricemia or precipitation of gout may occur in some patients.

Thiazides may decrease urinary calcium excretion and cause an intermittent and slight elevation of serum calcium in the absence of known disorders of calcium metabolism. Marked hypercalcemia may be evidence of hidden hyperparathyroidism. Thiazides, including hydrochlorothiazide should be discontinued prior to performing tests for parathyroid function.

There are reports of exacerbation or activation of systemic lupus erythematosus.

A greater blood pressure reduction and an increase in side effects may be observed in the elderly with hydrochlorothiazide.

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

Dialysis

Data not available

Other Comments

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

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