Captopril Pediatric Dose — Cardiovascular (ACE Inhibitor)
Captopril is an angiotensin-converting enzyme (ACE) inhibitor that reduces systemic vascular resistance by blocking the conversion of angiotensin I to angiotensin II. It is used in pediatric practice for the management of hypertension, heart failure, and afterload reduction in congenital heart disease. Oral captopril remains one of the most commonly used ACE inhibitors in neonates and young infants due to its well-characterized pharmacokinetics in this population.
Pediatric Dosing
| Age Group | Dose | Frequency |
|---|---|---|
| Neonates | 0.05–0.1 mg/kg/dose PO | Every 6–12 hours |
| Infants & Children | 0.2–0.5 mg/kg/dose PO | Every 6–12 hours |
| Adults | 6.25–25 mg/kg/dose PO; Max 6 mg/kg/day | BID–TID |
First Dose (Infants & Children): Administer 0.1 mg/kg as the initial test dose and monitor closely for hypotension before titrating to the target dose range.
Worked example: For a 10 kg infant using an initial dose of 0.1 mg/kg: 10 × 0.1 mg/kg = 1 mg for the first dose. Subsequent doses may be titrated up to 10 × 0.5 mg/kg = 5 mg/dose every 6–12 hours as tolerated.
Indications and Clinical Context
Captopril is indicated in pediatric patients for hypertension, congestive heart failure, and afterload reduction in the setting of left-to-right shunts or systolic dysfunction. In neonates, it is particularly utilized for renovascular hypertension and post-operative cardiac management, though extreme caution is warranted in this age group given heightened sensitivity to ACE inhibitor–related hypotension and renal impairment. Neonates are at increased risk for oliguria and azotemia, and dosing should be initiated at the lower end of the recommended range.
In older infants and children, captopril may be used as part of a broader cardiovascular management strategy for dilated cardiomyopathy or systemic hypertension. Dosing should be individualized and titrated based on blood pressure response and renal function. Consult institutional protocol for specific titration schedules and target dosing endpoints.
Administration and Monitoring
Captopril is administered orally. It may be compounded as a liquid formulation for neonates and infants who cannot swallow tablets. The first dose in infants and children should be 0.1 mg/kg, with the patient monitored for symptomatic hypotension for at least 1–2 hours following administration. Blood pressure, renal function (BUN, creatinine), serum potassium, and urine output should be monitored regularly, particularly during initiation and dose titration.
- Route: Oral (PO) only per this indication; compounded liquid available for young patients
- Key adverse effects: Hypotension (especially first dose), hyperkalemia, acute kidney injury, cough, and angioedema
- Contraindications: Bilateral renal artery stenosis, history of ACE inhibitor–associated angioedema, concomitant use with aliskiren in patients with diabetes or renal impairment
- Max dose (adults): 6 mg/kg/day; consult institutional protocol for pediatric maximum daily dose
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.