Pregnancy Risk Category C
How supplied
Tablets: 0.125 mg, 0.25 mg
Capsules: 0.05 mg, 0.1 mg, 0.2 mg
Elixir: 0.05 mg/ml
Injection: 0.05 mg/ml†, 0.1 mg/ml (pediatric), 0.25 mg/ml
Action
Inhibits sodium potassium-activated adenosine triphosphatase, thereby promoting movement of calcium from extracellular to intracellular cytoplasm and strengthening myocardial contraction. Also acts on CNS to enhance vagal tone, slowing conduction through the SA and AV nodes and providing an antiarrhythmic effect.
Indications & dosage
Heart failure, paroxysmal supraventricular tachycardia, atrial fibrillation and flutter--
Adults: loading dose is 0.5 to 1 mg I.V. or P.O. in divided doses over 24 hours; maintenance dose is 0.125 to 0.5 mg I.V. or P.O. daily (average is 0.25 mg). Depending on response, larger doses may be needed for arrhythmias.
Elderly: for patients over age 65, 0.125
mg P.O. daily as maintenance dose. Frail or underweight elderly patients may require only 0.0625 mg daily or 0.125 mg every other day.
Premature neonates: loading dose is 0.015 to 0.025 mg/kg I.V. in three divided doses over 24 hours; maintenance dose is 0.01 mg/kg daily, divided q 12 hours.
Neonates: loading dose is 0.025 to 0.035 mg/kg P.O., divided q 8 hours over 24 hours; I.V. loading dose is 0.02 to 0.03 mg/kg; maintenance dose is 0.01 mg/kg P.O. daily, divided q 12 hours.
Children ages 1 month to 2 years: loading dose is 0.035 to 0.06 mg/kg P.O. in three divided doses over 24 hours; I.V. loading dose is 0.03 to 0.05 mg/kg; maintenance dose is 0.01 to 0.02 mg/kg P.O. daily, divided q 12 hours.
Children over age 2: loading dose is 0.02 to 0.04 mg/kg P.O. daily, divided q 8 hours over 24 hours; I.V. loading dose is 0.025 to 0.035 mg/kg; maintenance dose is 0.012 mg/kg P.O. daily, divided q 12 hours.
Adjust-a-dose: Smaller loading and maintenance doses are given to patients with impaired renal function.
Adverse reactions
CNS: fatigue, generalized muscle weakness, agitation, hallucinations, headache, malaise, dizziness, vertigo, stupor, paresthesia.
CV: arrhythmias (most commonly, conduction disturbances with or without AV block, PVCs, and supraventricular arrhythmias); arrhythmias may lead to increased severity of heart failure and hypotension.
EENT: yellow-green halos around visual images, blurred vision, light flashes, photophobia, diplopia.
GI: anorexia, nausea, vomiting, diarrhea.
Interactions
Drug-drug. Amiloride: inhibited digoxin effect and increased digoxin excretion. Monitor for altered digoxin effect.
Amiodarone, diltiazem, nifedipine, quinidine, verapamil: increased digoxin blood levels. Monitor for toxicity.
Amphotericin B, carbenicillin, corticosteroids, diuretics (including loop diuretics, chlorthalidone, metolazone, thiazides), ticarcillin: hypokalemia predisposing patient to digitalis toxicity. Monitor serum potassium levels.
Antacids, kaolin-pectin: decreased absorption of oral digoxin. Schedule doses as far as possible from oral digoxin administration.
Anticholinergics: may increase digoxin absorption of oral digoxin tablets. Monitor blood levels and observe for toxicity.
Cholestyramine, colestipol, metoclopramide: decreased absorption of oral digoxin. Monitor for decreased digitoxin effect and low blood levels. Space doses by giving digoxin 11/2 hours before or 2 hours after other drugs.
Parenteral calcium, thiazides: hypercalcemia and hypomagnesemia predisposing patient to digitalis toxicity. Monitor serum calcium and serum magnesium levels.
Drug-herb. Betel palm, fumitory, lily of the valley, goldenseal, motherwort, rue, shepherd's purse: possible enhanced cardiac effects. Avoid concomitant use.
Licorice, oleander, Siberian ginseng, squill: possible enhanced toxicity. Monitor patient closely.
Effects on diagnostic tests
None reported.
Contraindications
Contraindicated in patients with digitalis-induced toxicity, ventricular fibrillation, ventricular tachycardia unless caused by heart failure, or hypersensitivity to drug.
Nursing considerations
I.V. administration
Patient teaching
*Liquid contains alcohol. **May contain tartrazine. †Canada ‡Australia §U.K. OTCOver the counter
Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE-THREATENING