Digoxin

Question 1

Class

Answer 1

Inotropic, cardiac glycoside, antiarrhythmic

Question 2

MOA

Answer 2

Rapid acting cardiac glycoside that increases the force of myocardial contraction, increases refractory period of the AV node (slows AV conduction). Indirectly increases intracardiac calcium concentration by inhibition of the Na/K pump, which increases cardiac contractility.

Question 3

Indications

Answer 3

CHF, rapid atrial arrhythmias, especially a-fib/ flutter.

Question 4

Contraindications

Answer 4

V-fib, digitalis toxicity, hypersensitivity

Question 5

Adverse reactions

Answer 5

Headache, weakness, blurred yellow or green vision, confusion, seizures, arrhythmias, n/v, or skin rash.

Question 6

Drug interactions

Answer 6

Amiodarone, verapamil, and quinidine May increase serum digoxin concentrations by 50-70%. Concurrent use of digoxin and verapamil May lead to severe heart block. Diuretics may potentiate cardiac toxicity.

Question 7

Dosage

Answer 7

Adult: loading dose of 0.25-0.50 mg slow IV/IO (or 4-6 mcg/kg over 5 min). Half for subsequent doses.

Pediatric: 10-50 mcg/kg slow IV/IO

Question 8

Duration

Answer 8

Onset: 5-30 mins IV
Peak: 30-120 minutes
Duration: Several Days

Question 9

Special considerations

Answer 9

Patients receiving digoxin must be placed on a cardiac monitor. Patients with chronic renal failure are prone to digoxin toxicity. Hypokalemia, hypomagnesaemia, and hypercalcemia potentiate digitalis toxicity.

Question 10

Pregnancy category

Answer 10

C

Question 11

How supplied

Answer 11

1mg in 2 mL vial