Therapeutic Classification: antiarrhythmics, inotropics
Pharmacologic Classification: digitalis glycosides
Absorption: 60–80% absorbed after oral administration of tablets; 70–85% absorbed after administration of elixir; 80% absorbed from IM sites (IM route not recommended due to pain/irritation). IV administration results in complete bioavailability.
Distribution: Widely distributed to tissues.
Metabolism/Excretion: Excreted almost entirely unchanged by the kidneys.
Half-life: 36–48 hr (↑ in renal impairment).
(antiarrhythmic or inotropic effects, provided that a loading dose has been given)
†Duration listed is that for normal renal function; in impaired renal function, duration will be longer.
CV: bradycardia, ECG changes, ARRHYTHMIAS, heart block.
EENT: blurred vision, yellow or green vision.
GI: anorexia, nausea, vomiting, diarrhea.
Hemat: thrombocytopenia.
Neuro: fatigue, headache, weakness.
For rapid effect, a larger initial loading dose should be given in several divided doses over 12–24 hr. Maintenance doses are determined for digoxin by renal function. All dosing must be evaluated by individual response. In general, doses required for atrial arrhythmias are higher than those for inotropic effect.
- IV, IM (Adults): Loading dose: 0.5–1 mg given as 50% of the dose initially and one quarter of the initial dose in each of 2 subsequent doses at 6–12 hr intervals.
- IV, IM (Children >10 yr): Loading dose: 8–12 mcg/kg given as 50% of the dose initially and one quarter of the initial dose in each of 2 subsequent doses at 6–12 hr intervals.
- IV, IM (Children 5–10 yr): Loading dose: 15–30 mcg/kg given as 50% of the dose initially and one quarter of the initial dose in each of 2 subsequent doses at 6–12 hr intervals.
- IV, IM (Children 2–5 yr): Loading dose: 25–35 mcg/kg given as 50% of the dose initially and one quarter of the initial dose in each of 2 subsequent doses at 6–12 hr intervals.
- IV, IM (Children 1–24 mo): Loading dose: 30–50 mcg/kg given as 50% of the dose initially and one quarter of the initial dose in each of 2 subsequent doses at 6–12 hr intervals.
- IV, IM (Infants –full term): Loading dose: 20–30 mcg/kg given as 50% of the dose initially and one quarter of the initial dose in each of 2 subsequent doses at 6–12 hr intervals.
- IV, IM (Infants –premature): Loading dose: 15–25 mcg/kg given as 50% of the dose initially and one quarter of the initial dose in each of 2 subsequent doses at 6–12 hr intervals.
- PO (Adults): Loading dose: 0.75–1.5 mg given as 50% of the dose initially and one quarter of the initial dose in each of 2 subsequent doses at 6–12 hr intervals. Maintenance dose: 0.125–0.5 mg/day depending on patient’s lean body weight, renal function, and serum level.
- PO (Geriatric Patients): Initial daily dose should not exceed 0.125 mg.
- PO (Children >10 yr): Loading dose: 10–15 mcg/kg given as 50% of the dose initially and one quarter of the initial dose in each of 2 subsequent doses at 6–12 hr intervals. Maintenance dose: 2.5–5 mcg/kg given daily as a single dose.
- PO (Children 5–10 yr): Loading dose: 20–35 mcg/kg given as 50% of the dose initially and one quarter of the initial dose in each of 2 subsequent doses at 6–12 hr intervals. Maintenance dose: 5–10 mcg/kg given daily in 2 divided doses.
- PO (Children 2–5 yr): Loading dose: 30–40 mcg/kg given as 50% of the dose initially and one quarter of the initial dose in each of 2 subsequent doses at 6–12 hr intervals. Maintenance dose: 7.5–10 mcg/kg given daily in 2 divided doses.
- PO (Children 1–24 mo): Loading dose: 35–60 mcg/kg given as 50% of the dose initially and one quarter of the initial dose in each of 2 subsequent doses at 6–12 hr intervals. Maintenance dose: 10–15 mcg/kg given daily in 2 divided doses.
- PO (Infants –full term): Loading dose: 25–35 mcg/kg given as 50% of the dose initially and one quarter of the initial dose in each of 2 subsequent doses at 6–12 hr intervals. Maintenance dose: 6–10 mcg/kg given daily in 2 divided doses.
- PO (Infants –premature): Loading dose: 20–30 mcg/kg given as 50% of the dose initially and one quarter of the initial dose in each of 2 subsequent doses at 6–12 hr intervals. Maintenance dose: 5–7.5 mcg/kg given daily in 2 divided doses.
