Heart Failure in Adults

LANOXIN is indicated for the treatment of mild to moderate heart failure in adults. LANOXIN increases left ventricular ejection fraction and improves heart failure symptoms as evidenced by improved exercise capacity and decreased heart failure-related hospitalizations and emergency care, while having no effect on mortality. Where possible, LANOXIN should be used in combination with a diuretic and an angiotensin-converting enzyme (ACE) inhibitor.

Heart Failure in Pediatric Patients

LANOXIN increases myocardial contractility in pediatric patients with heart failure.

Atrial Fibrillation in Adults

LANOXIN is indicated for the control of ventricular response rate in adult patients with chronic atrial fibrillation.

Important Dosing Information

In selecting a LANOXIN dosing regimen, it is important to consider factors that affect digoxin blood levels (e.g., body weight, age, renal function, concomitant drugs) since toxic levels of digoxin are only slightly higher than therapeutic levels. Dosing can be either initiated with a loading dose followed by maintenance dosing if rapid titration is desired or initiated with maintenance dosing without a loading dose.

Consider interruption or reduction in digoxin dose prior to electrical cardioversion [see WARNINGS AND PRECAUTIONS].

Use digoxin solution to obtain the appropriate dose in infants, young pediatric patients, or patients with very low body weight.

Loading Dosing Regimen in Adults and Pediatric Patients

For adults and pediatric patients if a loading dosage is to be given, administer half the total loading dose initially, then ¼ the loading dose every 4 to 8 hours twice, with careful assessment of clinical response and toxicity before each dose. The recommended loading dose is displayed in Table 1.

Table 1: Recommended LANOXIN Oral Loading Dose

Maintenance Dosing in Adults and Pediatric Patients Over 10 Years Old

The maintenance dose is based on the lean body weight, renal function, age, and concomitant products [see DRUG INTERACTIONS].

The recommended starting maintenance dosage in adults and pediatric patients over 10 years old is displayed in Table 2. Doses may be increased every 2 weeks according to clinical response, serum drug levels, and toxicity.

Table 2: Recommended Starting LANOXIN Maintenance Dosage in Adults and Pediatric Patients Over 10 Years Old

Table 3 displays the recommended (once daily) maintenance dose of LANOXIN in pediatric patients over 10 years old and adult patients according to lean body weight and renal function. The doses are based on studies in adult patients with heart failure. Alternatively, the maintenance dose may be estimated by the following formula (peak body stores lost each day through elimination):

Total Maintenance Dose = Loading Dose (i.e., Peak Body Stores) x % Daily Loss/100
(% Daily Loss = 14 + Creatinine clearance/5)

Reduce the dose of LANOXIN in patients whose lean weight is an abnormally small fraction of their total body mass because of obesity or edema.

Table 3: Recommended Maintenance Dose (in micrograms given once daily) of LANOXIN in Pediatric Patients Over 10 Years Old and Adults by Lean Body Weight and by Renal Function^a

Maintenance Dosing in Pediatric Patients Less Than 10 Years Old

The starting maintenance dose for heart failure in pediatric patients less than 10 years old is based on the lean body weight, renal function, age, and concomitant products [see DRUG INTERACTIONS]. The recommended starting maintenance dose for pediatric patients between 5 and 10 years old with normal renal function is displayed in Table 4.

Table 4: Recommended Starting LANOXIN Maintenance Dosage in Pediatric Patients Between 5 and 10 Years Old

The recommended maintenance dose (to be given twice daily) is presented in Table 5.

Table 5: Recommended Maintenance Dose (in micrograms given twice daily) of LANOXIN in Pediatric Patients < 10 Years of Age^a Based upon Lean Body Weight and Renal Function^a,b

Monitoring to Assess Safety, Efficacy, and Therapeutic Blood Levels

Monitor for signs and symptoms of digoxin toxicity and clinical response. Adjust dose based on toxicity, efficacy, and blood levels.

Serum digoxin levels < 0.5 ng/mL have been associated with diminished efficacy, while levels above 2 ng/mL have been associated with increased toxicity without increased benefit.

Interpret the serum digoxin concentration in the overall clinical context, and do not use an isolated measurement of serum digoxin concentration as the basis for increasing or decreasing the LANOXIN dose. Serum digoxin concentrations may be falsely elevated by endogenous digoxin-like substances [see DRUG INTERACTIONS]. If the assay is sensitive to these substances, consider obtaining a baseline digoxin level before starting LANOXIN and correct post-treatment values by the reported baseline level.

Obtain serum digoxin concentrations just before the next scheduled LANOXIN dose or at least 6 hours after the last dose. The digoxin concentration is likely to be 10% to 25% lower when sampled right before the next dose (24 hours after dosing) compared to sampling 8 hours after dosing (using once-daily dosing). However, there will be only minor differences in digoxin concentrations using twice daily dosing whether sampling is done at 8 or 12 hours after a dose.

Switching from Intravenous Digoxin to Oral Digoxin

When switching from intravenous to oral digoxin formulations, make allowances for differences in bioavailability when calculating maintenance dosages (see Table 6).

Table 6: Comparison of the Systemic Availability and Equivalent Doses of Oral and Intravenous LANOXIN

Dosage Forms And Strengths

Tablets: 125 micrograms are yellow, round, scored tablets with “Y3B” imprinted on one side. Tablets: 250 micrograms are white, round, scored tablets with “X3A” imprinted on one side.

Storage And Handling

LANOXIN (digoxin) Tablets, Scored 125 mcg (0.125 mg): Bottles of 100 with child-resistant cap (NDC 0173-0242-55) and 1,000 (NDC 0173-0242-75); unit dose pack of 100 (NDC 01730242-56). Imprinted with LANOXIN and Y3B (yellow).

LANOXIN (digoxin) Tablets, Scored 250 mcg (0.25 mg): Bottles of 100 with child-resistant cap (NDC 0173-0249-55), 1,000 (NDC 0173-0249-75), and 5,000 (NDC 0173-0249-80); unit dose pack of 100 (NDC 0173-0249-5656). Imprinted with LANOXIN and X3A (white).

Store at 25°C (77°F); excursions permitted to 15 to 30°C (59 to 86°F) in a dry place and protect from light. Keep out of reach of children.

Manufactured for : GlaxoSmithKline Research Triangle Park, NC 27709 by DSM Pharmaceuticals, Inc. Greenville, NC 27834 or GlaxoSmithKline Research Triangle Park, NC 27709. Revised: 08/2012

Last reviewed on RxList: 8/29/2012
This monograph has been modified to include the generic and brand name in many instances.