How should the nurse administer a digitalizing dose to a child prescribed digoxin

• What Is
  • What Is Digoxin and How Does It Work?
• Side Effects
  • What Are Side Effects Associated with Using Digoxin?
• Drug Interactions
  • What Other Drugs Interact with Digoxin?
• Warning and Precautions
  • What Are Warnings and Precautions for Digoxin?

What Is Digoxin and How Does It Work?

Digoxin is used to treat heart failure, usually along with other medications. It is also used to treat a certain type of irregular heartbeat (chronic atrial fibrillation). Treating heart failure may help maintain your ability to walk and exercise and may improve the strength of your heart. Treating an irregular heartbeat can decrease the risk for blood clots, an effect that may reduce your risk for a heart attack or stroke.

Digoxin belongs to a class of medications called cardiac glycosides. It works by affecting certain minerals (sodium and potassium) inside heart cells. This reduces strain on the heart and helps it maintain a normal, steady, and strong heartbeat.

Digoxin is available under the following different brand names: Lanoxin.

What Are Dosage of Digoxin?

Dosage of Digoxin:

Adult and Pediatric Dosage Forms and Strengths

Oral solution

• 0.05 mg/mL

Injectable solution

• 0.1 mg/mL
• 0.25 mg/mL

Tablet

• 0.0625 mg (Lanoxin only) (adult only)
• 0.125 mg
• 0.1875 mg (Lanoxin only) (adult only)
• 0.25 mg

Atrial Fibrillation

Rapid digitalizing (loading-dose) regimen

• Intravenous (IV): 8-12 mcg/kg (0.008-0.012 mg/kg) total loading dose; administer 50% initially; then may cautiously give 1/4 the loading dose every 6-8 hours twice; perform a careful assessment of clinical response and toxicity before each dose
• Oral: 10-15 mcg/kg total loading dose; administer 50% initially; then may cautiously give 1/4 the loading dose every 6-8 hours twice; perform a careful assessment of clinical response and toxicity before each dose

Maintenance

• Oral: 3.4-5.1 mcg/kg/day or 0.125-0.5 mg/day orally; may increase the dose every 2 weeks based on clinical response, serum drug levels, and toxicity
• Intravenous/intramuscular (IV/IM): 0.1-0.4 mg once/day; IM route not preferred due to severe injection site reaction

Heart Failure

• As per ACCF/AHA guidelines, a loading dose to initiate digoxin therapy in patients with heart failure is not necessary
• 0.125-0.25 mg orally/IV once/day; higher doses including 0.375-0.5 mg/day rarely needed
• Use lower end of dosing (0.125 mg/day) in patients with impaired renal function or low lean body mass

Heart Failure/Atrial Fibrillation, Pediatric

• Use doses at the lower end of the spectrum when treating heart failure
• Reduce dose by 20-25% when changing from the oral formulation or intramuscular (IM) to intravenous (IV) therapy
• Premature neonate
  • Oral: 1st loading dose, 10-15 mcg/kg; 2nd and 3rd loading doses, 5-7.5 mcg/kg every 6-8 hours for 2 doses; maintenance: 5-7.5 mcg/kg/day divided every 12 hours
  • Intravenous/intramuscular (IV/IM): 1st loading dose, 7.5-12.5 mcg/kg; 2nd and 3rd loading doses, 3.75-6.25 mcg/kg every 6-8 hours for 2 doses; maintenance: 4-6 mcg/kg/day divided every 12 hours
• Full-term neonate
  • Oral: 1st loading dose, 12.5-17.5 mcg/kg; 2nd and 3rd loading doses, 6.25-8.75 mcg/kg every 6-8 hours for 2 doses; maintenance: 6-10 mcg/kg/day divided every 12 hours
  • IV/IM: 1st loading dose, 10-15 mcg/kg; 2nd and 3rd loading doses, 5-7.5 mcg/kg every 6-8 hours for 2 doses; maintenance: 5-8 mcg/kg/day divided every 12 hours
• Infants and children 1-24 months
  • Oral: 1st loading dose, 17.5-30 mcg/kg; 2nd and 3rd loading doses, 8.75-15 mcg/kg every 6-8 hours for 2 doses; maintenance: 10-15 mcg/kg/day divided every 12 hours
  • IV/IM: 1st loading dose, 15-25 mcg/kg; 2nd and 3rd loading doses, 7.5-12.5 mcg/kg every 6-8 hours for 2 doses; maintenance: 7.5-12 mcg/kg/day divided every 12 hours
• 2-5 years
  • Oral: 1st loading dose, 15-20 mcg/kg; 2nd and 3rd loading doses, 8.75-10 mcg/kg every 6-8 hours for 2 doses; maintenance: 7.5-10 mcg/kg/day divided every 12 hours
  • IV/IM: 1st loading dose, 12.5-17.5 mcg/kg; 2nd and 3rd loading doses, 6.25-8.75 mcg/kg every 6-8 hours for 2 doses; maintenance: 6-9 mcg/kg/day divided every 12 hours
• 5-10 years
  • Oral: 1st loading dose, 10-17.5 mcg/kg; 2nd and 3rd loading doses, 5-8.75 mcg/kg every 6-8 hours for 2 doses; maintenance: 5-10 mcg/kg/day divided every 12 hours
  • IV/IM: 1st loading dose, 7.5-15 mcg/kg; 2nd and 3rd loading doses, 3.75-7.5 mcg/kg every 6-8 hours for 2 doses; maintenance: 4-8 mcg/kg/day divided every 12 hours
• Older than 10 years and less than 100 kg
  • Oral: 1st loading dose, 5-7.5 mcg/kg; 2nd and 3rd loading doses, 2.5-3.75 mcg/kg every 6-8 hours for 2 doses; maintenance: 2.5-5 mcg/kg/day
  • IV/IM: 1st loading dose, 4-6 mcg/kg; 2nd and 3rd loading doses, 2-3 mcg/kg every 6-8 hours for 2 doses; maintenance: 2-3 mcg/kg/day

Dosing Modifications

• Adjust maintenance dose by estimating renal clearance and measuring serum levels
• In heart failure, higher dosages have no additional benefit and may increase toxicity; decreased renal clearance may lead to increased toxicity
• In geriatric patients, use lean body weight to calculate dose

SLIDESHOW

What Are Warnings and Precautions for Digoxin?

Warnings

• This medication contains digoxin
• Do not take Lanoxin if you are allergic to digoxin or any ingredients contained in this drug
• Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately

Contraindications

• Hypersensitivity
• Ventricular fibrillation

Effects of Drug Abuse

• No information available

Short-Term Effects

• See "What Are Side Effects Associated with Using Digoxin?"

Long-Term Effects

• See "What Are Side Effects Associated with Using Digoxin?"

Cautions

• Use caution in chronic constrictive pericarditis, electrical cardioversion, severe bradycardia, severe heart failure, severe pulmonary disease, sick sinus syndrome, ventricular tachycardia, ventricular premature contractions,
• Wolff-Parkinson-White syndrome, electrolyte imbalance, hypothyroidism or hyperthyroidism, hypoxia, idiopathic hypertrophic subaortic stenosis, renal disease, concomitant diuretics.
• Not recommended in patients with acute myocardial infarction.
• Avoid in patients with myocarditis.
• Risk of advanced or complete heart block in patients with sinus node disease and AV block.
• Very narrow margin between effective therapeutic and toxic dosages: Therapeutic range, 0.5-2 ng/mL (target 0.5-1 ng/mL); toxic range, greater than 2.5 ng/mL.
• Generally avoid if left ventricular systolic function preserved, although may be used for ventricular rate control in the subgroup with chronic atrial fibrillation.
• Less effective in presence of hypokalemia or hypocalcemia; avoid hypercalcemia or hypomagnesemia, which may predispose to serious arrhythmias.
• Heart failure patients with preserved ventricular function including acute cor pulmonale, amyloid heart disease, and constrictive pericarditis may be susceptible to digoxin toxicity.
• May cause false-positive ST-T changes during exercise testing.
• Do not switch between different oral forms or between brand and generic forms of digoxin; bioavailability varies.
• Serum levels drawn within 6-8 hours of the dose will be falsely high because of the prolonged distribution phase.
• Increased risk of estrogen-like effects in geriatric patients.
• Beriberi heart disease may not respond adequately if underlying thiamine deficiency is not corrected.
• Atrial arrhythmias are difficult to treat if associated with hypermetabolic (hyperthyroidism) or hyperdynamic (hypoxia) states; treat the underlying condition before initiating therapy.
• Avoid extravasation; ensure proper needle or catheter placement prior to and during administration.
• Monitor for pro-arrhythmic effects, especially with digoxin toxicity.
• Use caution in patients with acute myocardial infarction; may increase myocardial oxygen demand; during acute coronary syndrome, digoxin administered intravenously (IV) may be used to slow a rapid ventricular response and improve left ventricular function in the acute treatment of atrial fibrillation associated with severe LV function and heart failure or hemodynamic instability.
• Monitor serum concentration closely when used for rate control in patients with atrial fibrillation; serum concentrations that are not properly controlled are associated with increased risk of mortality.
• Consider the use of digoxin only in heart failure with reduced ejection fraction when symptoms remain despite guideline-directed medical therapy; withdrawal of digoxin in clinically stable patients with heart failure may lead to the recurrence of heart failure symptoms.
• In hypertrophic cardiomyopathy, outflow obstruction may worsen due to positive inotropic effects of digoxin; avoid use unless used to control ventricular response with atrial fibrillation; in the absence of atrial fibrillation, digoxin is potentially harmful in the treatment of dyspnea in patients with hypertrophic cardiomyopathy.
• Avoid rapid IV administration in digitalized patients; may produce serious arrhythmias.
• Not necessary to routinely reduce or hold digoxin therapy prior to elective electrical cardioversion for atrial fibrillation; however, exclusion of digoxin toxicity is necessary prior to cardioversion; withhold digoxin and delay cardioversion until toxicity subsides if signs of digoxin excess exist.

Pregnancy and Lactation

• Use Digoxin with caution during pregnancy if benefits outweigh risks
• Animal studies show risk and human studies are not available, or neither animal nor human studies were done
• Digoxin enters breast milk; use with caution if breastfeeding (American Academy of Pediatrics committee states, "compatible with nursing")

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