Digoxin

Digoxin

Drug monograph · NCLEX study reference
Trade names	Lanoxin
Therapeutic class	Heart failure agent, antiarrhythmic
Pharmacologic class	Cardiac glycoside (NTI)
Onset / peak / duration	PO onset 1 to 2 hours; IV onset 5 to 30 minutes; duration 3 to 4 days.
Half-life / level	Half-life 36 to 48 hours; therapeutic level about 0.5 to 2 ng/mL (lower, around 0.5 to 0.9 ng/mL, preferred in heart failure).
Routes	PO (oral)
High-alert (ISMP)	Yes
Black box warning	None
Antidote / reversal	Digoxin immune Fab (DigiFab) for severe toxicity.
Pregnancy / lactation	Used when clearly needed.

Nursing pharmacology study reference (NCLEX-style monograph). Numeric values are standard teaching ranges for study and must be verified against current manufacturer labeling before clinical use. This is educational content, not prescribing guidance.

Digoxin (brand name Lanoxin) — Heart failure agent, antiarrhythmic; Cardiac glycoside (NTI).

Identification

• Therapeutic class: Heart failure agent, antiarrhythmic.
• Pharmacologic class: Cardiac glycoside (NTI).

Pharmacology

• Mechanism of action: Inhibits the sodium-potassium pump to increase intracellular calcium and contractility (positive inotrope), and slows AV conduction to reduce heart rate.
• Onset / peak / duration: PO onset 1 to 2 hours; IV onset 5 to 30 minutes; duration 3 to 4 days.
• Half-life / therapeutic level: Half-life 36 to 48 hours; therapeutic level about 0.5 to 2 ng/mL (lower, around 0.5 to 0.9 ng/mL, preferred in heart failure).

Clinical use

• Indications: Heart failure, atrial fibrillation rate control.
• Usual dose, route, frequency: 0.125 to 0.25 mg PO daily, sometimes with a loading approach.
• Maximum dose / adjustments: Reduce dose in renal impairment and in the elderly; hypokalemia greatly increases toxicity risk.

Safety

• Contraindications: Ventricular fibrillation, second or third degree heart block without pacemaker.
• Black box warning: None formal; narrow therapeutic index demands careful monitoring.
• Interactions: Diuretics (hypokalemia raises toxicity), amiodarone, verapamil, and quinidine (raise digoxin levels); hawthorn and licorice (herbal) affect levels and potassium.
• Pregnancy / lactation: Used when clearly needed.
• High-alert: Yes.

Adverse effects

• Common side effects: Bradycardia, nausea, fatigue.
• Serious effects to report: Toxicity signs: anorexia, nausea, vomiting, visual changes (yellow or green halos), confusion, arrhythmias.
• Antidote / reversal: Digoxin immune Fab (DigiFab) for severe toxicity.

Nursing process

• Assessment before administration: Apical pulse for one full minute, potassium, renal function, digoxin level.
• Interventions during therapy: Hold and notify if apical pulse is below 60 in adults; correct hypokalemia.
• Monitor: Apical heart rate, potassium, renal function, digoxin level, ECG.
• Evaluation / expected outcome: Improved heart failure symptoms, controlled ventricular rate.

Patient teaching

• Patient teaching: Learn to take your pulse; report nausea or vision changes.
• Notify provider if: Pulse below 60, nausea or appetite loss, yellow or green vision, confusion.
• Administration tips: Same time daily; do not take with high-fiber meals at the same time; do not double doses.