Adult Dosing
CHF
- Digitalizing dose: 0.5-1 mg IM/IV given as 50% initially; then 25% x 2 q6–12 hrs
- Maintenance dose: 0.125–0.5 mg/day PO or 0.125-0.35 mg/day IV
- Note: 0.1 mg IM/IV = 0.125 mg tab/soln
Atrial fibrillation/Atrial flutter/Paroxysmal atrial tachycardia
- Digitalizing dose: 0.5-1 mg IM/IV given as 50% initially; then 25% x 2 q6–12 hrs
- Maintenance dose: 0.125–0.5 mg/day PO or 0.125-0.35 mg/day IV
- Note: 0.1 mg IM/IV = 0.125 mg tab/soln
Pediatric Dosing
CHF/Supraventricular tachycardias
- It cannot be overemphasized that dosage guidelines provided are based upon average patient response and substantial individual variation can be expected. Accordingly, ultimate dosage selection must be based upon clinical assessment of the patient.
- Neonates premature
- Loading dose: 15-25 mcg/kg IM/IV given as 50% initially; then 25% x 2 q6–12 hrs
- Maintenance dose: 4-6 mcg/kg/day
- Neonates; fullterm
- Loading dose: 20-30 mcg/kg IM/IV given as 50% initially; then 25% x 2 q6–12 hrs
- Maintenance dose: 5-8 mcg/kg/day
- 1-24 mo
- Loading dose: 30-50 mcg/kg IM/IV given as 50% initially; then 25% x 2 q6–12 hrs
- Maintenance dose: 7.5-12 mcg/kg/day
- 2-5 yrs
- Loading dose: 25-35 mcg/kg IM/IV given as 50% initially; then 25% x 2 q6–12 hrs
- Maintenance dose: 6-9 mcg/kg/day
- 5-10 yrs
- Loading dose: 15-30 mcg/kg IM/IV given as 50% initially; then 25% x 2 q6–12 hrs
- Maintenance dose: 4-8 mcg/kg/day
- > 10 yrs
- Loading dose: 8-12 mcg/kg IM/IV given as 50% initially; then 25% x 2 q6–12 hrs
- Maintenance dose: 2-3 mcg/kg/day
[Outline]
Renal Dose Adjustment (Based on CrCl):
- Loading doses: Decrease dose in proportion to the renal impairment (based upon peak digoxin body stores of 6-10 mcg/kg)
Hepatic Dose Adjustment
- Dosage adjustment not defined
- Parenteral administration of digoxin should be considered only when the need for rapid digitalization is urgent or when the drug cannot be taken orally
- Intramuscular injection can lead to severe pain at the injection site, thus IV route is preferred
- Digoxin slows sinoatrial and AV conduction and prolongs the PR interval. It may cause severe sinus bradycardia or sinoatrial block in pre-existing sinus node disease and may cause advanced or complete heart block in patients with pre-existing incomplete AV block
- In patients with paroxysmal atrial fibrillation or flutter and a coexisting accessory AV pathway, increased antegrade conduction across the accessory pathway leading to rapid ventricular response or ventricular fibrillation may occur. Do not use in such patients unless conduction down the accessory pathway has been blocked (by surgery or by pharmacotherapy)
- Signs of toxicity may occur (eg, abdominal pain, anorexia, nausea, vomiting, visual disturbance, bradycardia, ECG changes, arrhythmias, headache, seizure). Digoxin antibodies (digoxin-immune Fab) for severe overdose toxicity may be required
- Therapeutic drug levels: CHF: 0.5-0.8 ng/mL; AF: 0.8-2 ng/mL; Toxic Levels: >2 ng/mL
- Consider patient specific characteristics (weight, age, creatinine clearance, factors likely to alter pharmacokinetic/dynamic profile of digoxin) when dosing
- Severe intoxication may cause hyperkalemia and bradycardia
- Heart failure may respond at lower levels (
0.5 ng/mL) while atrial fibrillation may need higher doses - Monitor serum Cr, electrolytes, HR at baseline, then periodically
- Monitor serum drug levels
- Hypothyroid patients are highly sensitive to glycosides where as hyperthyroid patients may need larger doses
Cautions: Use cautiously in
Pregnancy Category:C
Breastfeeding: Probably safe; due to low levels of digoxin in breastmilk, amounts ingested by the infant are small and would not be expected to cause any adverse effects. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT ). This drug is considered safe and compatible with breastfeeding based upon data from AAP Policy Guidelines (available at http://aappolicy.aappublications.org/cgi/content/full/pediatrics;108/3/776 last accessed 26 October 2009)
