LANOXIN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for LANOXIN (LANOXIN).
Inhibits Na+/K+ ATPase, increasing intracellular Ca2+ via Na+/Ca2+ exchange, enhancing cardiac contractility and reducing conduction through AV node.
| Metabolism | Primarily hepatic via CYP3A4 and renal excretion of unchanged drug; undergoes biliary excretion and enterohepatic recirculation. |
| Excretion | Renal excretion of unchanged drug (60-80%) and biliary/fecal elimination (20-40%). |
| Half-life | Terminal elimination half-life is approximately 36-48 hours in patients with normal renal function; prolonged to 3.5-5 days in anuria. |
| Protein binding | 25-30% bound primarily to albumin. |
| Volume of Distribution | Vd approximately 6-7 L/kg; indicates extensive tissue binding, particularly to cardiac muscle. |
| Bioavailability | Oral: 60-80%; Intravenous: 100%. |
| Onset of Action | Oral: 0.5-2 hours; Intravenous: 5-30 minutes. |
| Duration of Action | Oral: 3-6 days; Intravenous: 3-6 days; clinical effects persist as long as drug is present. |
| Action Class | Cardiac glycosides |
| Brand Substitutes | Digitran 0.25mg Tablet, Sangoxin 0.25mg Tablet, Cardioxin 0.25mg Tablet, Digoxin 0.25mg Tablet, Geoxin 0.25mg Tablet |
0.125-0.25 mg orally once daily; loading dose 0.5-0.75 mg orally divided over 24-48 hours if rapid digitalization required.
| Dosage form | INJECTABLE |
| Renal impairment | GFR >50 mL/min: no adjustment; GFR 10-50 mL/min: reduce dose by 50% or use 0.125 mg every 48 hours; GFR <10 mL/min: reduce dose by 75% or use 0.0625 mg daily; monitor digoxin levels. |
| Liver impairment | No specific Child-Pugh based dose adjustment; use caution in severe hepatic impairment due to potential toxicity; monitor levels. |
| Pediatric use | Loading dose: 10-15 mcg/kg orally divided every 8 hours over 24 hours; maintenance: 5-10 mcg/kg/day orally in 2 divided doses; maximum 0.25 mg/day. |
| Geriatric use | Start with 0.0625-0.125 mg orally daily; adjust based on renal function and drug levels; due to decreased lean body mass and renal clearance. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for LANOXIN (LANOXIN).
| Breastfeeding | Digoxin is excreted into breast milk in low concentrations. M/P ratio approximately 0.6–0.9. At typical maternal doses (0.125–0.5 mg/day), the estimated infant dose is less than 10% of the weight-adjusted neonatal maintenance dose, usually considered compatible with breastfeeding. Monitor infant for signs of digoxin toxicity (bradycardia, poor feeding, vomiting). |
| Teratogenic Risk | Digoxin crosses the placenta. First trimester: No increased risk of major malformations reported in human studies; animal studies show no teratogenicity at clinically relevant doses. Second/third trimester: Risk of fetal toxicity (bradycardia, arrhythmias) if maternal serum levels are supratherapeutic; therapeutic maternal levels are generally safe. Chronic use may be associated with reduced birth weight. |
■ FDA Black Box Warning
None; however, toxicity is common and potentially fatal. Not a formal black box warning due to age of drug.
| Serious Effects |
["Hypersensitivity","Ventricular fibrillation","AV block (unless pacemaker present)","Wolff-Parkinson-White syndrome with atrial fibrillation","Hypertrophic obstructive cardiomyopathy","Hypokalemia or hypercalcemia (relative)"]
| Precautions | ["Toxicity risk: hypokalemia, hypomagnesemia, hypercalcemia increase sensitivity","Renal impairment requires dose adjustment","Digoxin immune Fab for life-threatening overdose","Pregnancy category C","Monitor serum levels and ECG"] |
Loading safety data…
| Fetal Monitoring | Maternal: Serum digoxin levels (therapeutic range 0.5–2.0 ng/mL), renal function, electrolytes (especially potassium, magnesium, calcium), ECG for rhythm and signs of toxicity, symptoms of toxicity (nausea, visual disturbances, arrhythmias). Fetal: Ultrasound for heart rate and rhythm, fetal heart rate monitoring in cases of high maternal doses or toxicity. |
| Fertility Effects | Digoxin has no known direct adverse effects on fertility in males or females. However, the underlying cardiac condition being treated may impact fertility; optimal disease control is recommended. |