Chlorothiazide Pediatric Dose — Diuretics
Chlorothiazide is a thiazide diuretic that inhibits sodium and chloride reabsorption in the distal convoluted tubule, promoting water excretion. It is used in pediatric patients for the management of edema associated with conditions such as congestive heart failure, hepatic cirrhosis, and renal disease. In infants, it is also employed in the management of bronchopulmonary dysplasia-associated fluid retention.
Pediatric Dosing
Dosing is age-stratified and administered orally every 12 hours:
- Age <6 months: 10–20 mg/kg/dose PO every 12 hours
- Age >6 months: 10 mg/kg/dose PO every 12 hours
Worked example — infant <6 months, 4 kg: At 10 mg/kg/dose → 4 × 10 mg/kg = 40 mg/dose PO every 12 hours; at the upper range of 20 mg/kg/dose → 4 × 20 mg/kg = 80 mg/dose PO every 12 hours.
Worked example — child >6 months, 15 kg: 15 × 10 mg/kg = 150 mg/dose PO every 12 hours. Consult institutional protocol for maximum single-dose limits, as the source description does not specify a ceiling dose.
Indications and Clinical Context
Chlorothiazide is indicated in pediatric patients for the management of edema and fluid overload states, including those secondary to congestive heart failure, nephrotic syndrome, and hepatic disease. In neonates and young infants, it is frequently prescribed alongside spironolactone for chronic diuresis in bronchopulmonary dysplasia. Unlike loop diuretics, thiazides act at the distal tubule and are generally preferred for mild-to-moderate, chronic fluid management rather than acute diuresis.
The higher weight-based dose range permitted in infants younger than 6 months reflects the reduced renal tubular responsiveness observed in this age group. Clinical response and electrolyte status should guide dose titration within the stated range.
Administration and Monitoring
Chlorothiazide is administered orally and is available as a suspension (250 mg/5 mL) for accurate dosing in young infants. It may be given with or without food, though consistent administration relative to meals is advisable. Because the oral suspension contains sorbitol, gastrointestinal intolerance (diarrhea, abdominal discomfort) may occur.
- Electrolytes: Monitor serum sodium, potassium, chloride, and bicarbonate regularly; hypokalemia, hyponatremia, and hypochloremic metabolic alkalosis are the most clinically relevant adverse effects.
- Fluid status: Assess weight, urine output, and signs of dehydration or excessive diuresis, particularly in neonates.
- Glucose and uric acid: Thiazides may cause hyperglycemia and hyperuricemia with prolonged use.
- Contraindications: Anuria and known hypersensitivity to sulfonamide-derived drugs.
Disclaimer: This article is an educational reference summarizing standard pediatric dosing values. It is not a substitute for clinical judgment. Always verify doses against institutional protocols, the current edition of authoritative references (e.g., Lexicomp, Harriet Lane Handbook, PALS guidelines), the patient’s accurate weight, and any patient-specific factors (renal/hepatic function, allergies, comedications) before administration.