Digoxin
Other
IV Dose | Any IV dose should be 75% of corresponding oral dose (see below) |
Oral dose | Dosing guidelines are largely a theological issue among pediatric cardiologists. Total oral digitalizing dose (TDD) given over 24 hours: Prematures: 20 ug/kg Full term newborns: 30 ug/kg Infants < 2years: 40-50 ug/kg Children >2 years: 30-40 ug/kg Adults: 1.25-1.5 mg total dose. Maintenance: 25% of TDD, daily divided BID. |
Levels | Life is too short to argue about whether digoxin levels are meaningful, other than in suspected toxicity. Column-separated levels in infants. O.7-2.0 nanograms/ml in adults. Levels up to 3.5 are well tolerated in infants |
Kinetics | Infants and children have high volumes of distribution. Elimination half-life by age: Prematures: 61 hours. Full term newborns: 35 hours Infants: 18 hours. Children: 37 hours. Adults: 35-48 hours. |
Cautions | Most common arrhythmias due to toxicity are PVCs and VT in adults, PAT with block in children |
Interactions | Levels increased by erythromycin, quinidine, amiodarone, verapamil and aldactone. (!) Levels decreased by phenytoin. Digoxin toxic arrhythmias exacerbated by bretylium due to initial catechol release from nerve terminals |
Preparations | Lanoxin scored tablets: 0.125, 0.250. 0.500 mg Lanoxicaps (solution in capsule): 50, 100, 200 ug. Lanoxin elixir (60 cc dropper bottle): 50 ug/ml. Lanoxin injection, Adult: 500 ug/2 ml Pediatric:100 ug/1 ml |
FDA approval in children | One of the few! |