chlorthalidone(redirected from Apo-Chlorthalidone)
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Pharmacologic class: Thiazide-like diuretic
Therapeutic class: Diuretic, antihypertensive
Pregnancy risk category B
Unclear. Enhances excretion of sodium, chloride, and water by interfering with transport of sodium ions across renal tubular epithelium. Also may dilate arterioles.
Tablets: 15 mg, 25 mg, 50 mg, 100 mg
Indications and dosages
➣ Edema associated with heart failure, renal dysfunction, cirrhosis, corticosteroid therapy, and estrogen therapy
Adults: 50 to 100 mg/day (30 to 60 mg Thalitone) P.O. or 100 mg every other day (60 mg Thalitone) P.O., up to 200 mg/day (120 mg Thalitone) P.O.
➣ Management of mild to moderate hypertension
Adults: 25 mg/day (15 mg Thalitone) P.O. Based on patient response, may increase to 50 mg/day (30 to 50 mg Thalitone) P.O., then up to 100 mg/day (except Thalitone) P.O.
• Hypersensitivity to drug, other thiazides, sulfonamides, or tartrazine
• Renal decompensation
Use cautiously in:
• renal or severe hepatic disease, abnormal glucose tolerance, gout, systemic lupus erythematosus, hyperparathyroidism, bipolar disorder
• elderly patients
• pregnant or breastfeeding patients.
• Know that dosages above 25 mg/day are likely to increase potassium excretion without further increasing sodium excretion or reducing blood pressure.
CNS: dizziness, vertigo, drowsiness, lethargy, confusion, headache, insomnia, nervousness, paresthesia, asterixis, nystagmus, encephalopathy
CV: hypotension, ECG changes, chest pain, arrhythmias, thrombophlebitis
GI: nausea, vomiting, cramping, anorexia, pancreatitis
GU: polyuria, nocturia, erectile dysfunction, loss of libido
Hematologic: blood dyscrasias
Metabolic: gout attack, dehydration, hyperglycemia, hypokalemia, hypocalcemia, hypomagnesemia, hyponatremia, hypophosphatemia, hyperuricemia, hyperlipidemia,
Musculoskeletal: muscle cramps, muscle spasms
Skin: flushing, photosensitivity, hives, rash, exfoliative dermatitis, toxic epidermal necrolysis
Other: fever, weight loss, hypersensitivity reactions
Drug-drug. Allopurinol: increased risk of hypersensitivity reaction
Amphotericin B, corticosteroids, mezlocillin, piperacillin, ticarcillin: additive hypokalemia
Antihypertensives, barbiturates, nitrates, opiates: increased hypotension
Cholestyramine, colestipol: decreased chlorthalidone blood level
Digoxin: increased risk of hypokalemia
Lithium: increased risk of lithium toxicity
Nonsteroidal anti-inflammatory drugs: decreased diuretic effect
Drug-diagnostic tests. Bilirubin, calcium, creatinine, uric acid: increased levels
Glucose (in diabetic patients): increased blood and urine levels
Magnesium, potassium, protein-bound iodine, sodium, urine calcium: decreased levels
Drug-herbs. Ginkgo: decreased antihypertensive effects
Licorice, stimulant laxative herbs (aloe, cascara sagrada, senna): increased risk of potassium depletion
Drug-behaviors. Acute alcohol ingestion: additive hypotension
Sun exposure: increased risk of photosensitivity
• Closely monitor patient with renal insufficiency.
• Assess for signs and symptoms of hematologic disorders.
• Monitor CBC with white cell differential and serum uric acid and electrolyte levels.
• Assess for signs and symptoms of hypersensitivity reactions, especially dermatitis.
• Watch for fluid and electrolyte imbalances.
• Instruct patient to consume a low-sodium diet containing plenty of potassium-rich foods and beverages (such as bananas, green leafy vegetables, and citrus juice).
• Caution patient to avoid driving and other hazardous activities until he knows whether drug makes him dizzy or affects concentration and alertness.
• Tell patient with diabetes to check urine or blood glucose level frequently.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above.