Class: Thiazide diuretic
- Tablets 25 mg
- Tablets 50 mg
- Tablets 100 mg
- Tablets 15 mg
Inhibits reabsorption of sodium and chloride in proximal portion of distal convoluted tubules.
Excreted in breast milk.
The t ½ is 40 h.
2 to 3 h.
2 to 6 h.
24 to 72 h.
Indications and Usage
Reduction of edema associated with CHF, hepatic cirrhosis, renal function impairment, corticosteroid and estrogen therapy; management of hypertension.
Treatment of calcium nephrolithiasis, osteoporosis, diabetes insipidus.
Hypersensitivity to thiazides, related diuretics, or sulfonamide-derived drugs; anuria; renal decompensation.
Dosage and AdministrationEdema
PO 50 to 200 mg daily or on alternate days.Hypertension
PO 25 to 100 mg daily. Doses above 25 mg/day potentiate potassium excretion but do not benefit sodium excretion or BP reduction.
Concurrent use may increase incidence of hypersensitivity reactions to allopurinol.Amphotericin B, corticosteroids
May intensify potassium depletion.Anticholinergics
May increase chlorthalidone absorption.Anticoagulants
May diminish anticoagulant effects.Bile acid sequestrants
May reduce chlorthalidone absorption. Give chlorthalidone at least 2 h before bile acid sequestrant.Calcium salts
Hypercalcemia may develop.Diazoxide
May cause hyperglycemia.Digitalis glycosides
Diuretic-induced hypokalemia and hypomagnesemia may precipitate digitalis-induced arrhythmias.Lithium
May decrease renal excretion of lithium.Loop diuretics
Synergistic effects may result in profound diuresis and serious electrolyte abnormalities.Methenamines, NSAIDs
May decrease effectiveness of chlorthalidone.Sulfonylureas, insulin
May decrease hypoglycemic effect of sulfonylureas.
Laboratory Test Interactions
Increased serum bilirubin levels. Serum magnesium levels in uremic patients may be increased.
Dizziness; lightheadedness; vertigo; headache; paresthesias; weakness; restlessness; insomnia.
Purpura; photosensitivity; rash; urticaria; necrotizing angiitis; vasculitis; cutaneous vasculitis; exfoliative dermatitis; toxic epidermal necrolysis.
Xanthopsia (yellow vision).
Anorexia; gastric irritation; nausea; vomiting; abdominal pain or cramping; bloating; diarrhea; constipation; pancreatitis.
Impotence; reduced libido.
Leukopenia; thrombocytopenia; agranulocytosis; aplastic or hypoplastic anemia.
Hyperglycemia; glycosuria; hyperuricemia; fluid and electrolyte imbalances.
Muscle cramps or spasms.
Category B .
Excreted in breast milk.
Safety and efficacy not established.
May occur in patients with or without history of allergy or bronchial asthma; cross-sensitivity with sulfonamides also may occur.
May precipitate azotemia; use with caution.
Minor alterations of fluid and electrolyte balance may precipitate hepatic coma; use with caution.
May cause increased concentrations of total serum cholesterol, total triglycerides, and LDL in some patients.
Antihypertensive effects may be enhanced.
Orthostatic hypotension, dizziness, drowsiness, syncope, potassium depletion, nausea, vomiting, lethargy, coma, GI irritation, GI hypermotility, seizures.
- Teach patient signs and symptoms of hypokalemia (eg, weakness, cramps, nausea, dizziness), especially if patient is taking digitalis.
- Explain diuretic effects of drug so patient is aware of expected and potential outcomes.
- Instruct patient to follow low-sodium diet to enhance action of medication.
- If high-potassium diet is recommended by health care provider, help patient identify appropriate meal plans or potassium supplements.
- Teach patient to record weight daily at a consistent time and to notify health care provider if weight fluctuates 5 or more pounds.
- Tell patient to notify health care provider of salt or water retention occurs (eg, swelling of feet, ankles, calves).
- Caution patient to avoid exposure to sunlight and to use sunscreen or wear protective clothing to avoid photosensitivity reaction.
- Advise patient to avoid sudden position changes to prevent orthostatic hypotension. Have patient get up slowly and dangle feet before getting out of bed.
Copyright © 2009 Wolters Kluwer Health.
More about chlorthalidone
- Other brands: Thalitone