Digoxin Pediatric Dose — Cardiovascular
Digoxin is a cardiac glycoside that exerts its effects by inhibiting the Na⁺/K⁺-ATPase pump, increasing intracellular calcium and enhancing myocardial contractility while slowing atrioventricular (AV) nodal conduction. It is used in pediatric patients for the management of heart failure and certain supraventricular tachyarrhythmias, including SVT and atrial flutter. Its narrow therapeutic index requires careful weight-based dosing and monitoring.
Pediatric Dosing
The total digitalizing dose (TDD) varies by patient age and clinical setting; consult institutional protocol or a current formulary reference for age-specific TDD guidance. Maintenance dosing is as follows:
- Maintenance (PO or IV): 5–10 mcg/kg/day, divided every 12 hours (BID)
Worked example — For a 20 kg child: 20 × 5 mcg/kg/day = 100 mcg/day (low end) and 20 × 10 mcg/kg/day = 200 mcg/day (high end), administered as two equally divided doses every 12 hours (50–100 mcg per dose). Always verify the calculated dose against age-appropriate reference ranges and serum digoxin levels before administration.
Indications and Clinical Context
Digoxin maintenance therapy is indicated in pediatric patients with heart failure due to systolic dysfunction and in those with chronic or recurrent supraventricular tachyarrhythmias requiring rate control. It remains an adjunctive agent in pediatric heart failure management, particularly in settings where beta-blockers or ACE inhibitors may be insufficient alone. Because the total digitalizing dose is age-dependent, clinicians should reference current pediatric formulary guidelines or cardiology institutional protocols to determine appropriate loading strategies prior to initiating maintenance therapy.
Serum digoxin concentrations, renal function, and electrolyte status (particularly potassium and magnesium) should be established before and during therapy, as alterations can significantly affect both drug levels and toxicity risk.
Administration and Monitoring
Digoxin may be administered orally (elixir or tablet) or intravenously. IV doses are generally 75–80% of the oral dose; consult institutional protocol for IV-equivalent conversion. Administer IV doses slowly over at least 5 minutes. Monitor for signs of digoxin toxicity including bradycardia, heart block, nausea, vomiting, and visual disturbances.
- Monitor serum digoxin levels (therapeutic range typically 0.5–2 ng/mL; lower targets preferred in heart failure)
- Assess renal function before and periodically during therapy; dose adjustment required in renal impairment
- Monitor serum potassium, magnesium, and calcium — hypokalemia and hypomagnesemia potentiate toxicity
- Use with caution in patients with AV block, hypertrophic cardiomyopathy, or Wolff-Parkinson-White syndrome
- Numerous drug interactions exist (e.g., amiodarone, quinidine, verapamil) that can elevate digoxin levels
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.