Indications: Heart failure, supraventricular arrhythmias (particularly atrial fibrillation).

Cautions: Recent myocardial infarction, hypothyroidism; reduce dose in elderly and in renal failure; avoid hypokalaemia or hypomagnesaemia. Note: Several drug–drug interactions; need to monitor therapeutic drug levels.

Contra-indications: Heart block, supraventricular arrhythmias caused by Wolff-Parkinson-White syndrome, ventricular tachycardia or fibrillation.

Side Effects: Usually associated with excessive dosage, include: anorexia, nausea, vomiting, diarrhea and abdominal pain; visual disturbances, headache, fatigue, drowsiness, confusion, dizziness, delirium, hallucinations, depression; arrhythmias, heart block; gynecomastia with long-term use.

Dose: It has to be adjusted individually for each patient and the indicated doses are intended only as an initial guide.

By mouth, rapid digitalization, 1 – 1.5 mg in divided doses over 24 hours.

Less urgent digitalization, 125-250 mcg twice daily for up to 1 week.

Maintenance, 0.125 - 0.25 mg once daily according to renal function status.

By IV infusion, for very rapid control, digitalizing dose of 0.75 – 1.25 mg in 50 ml over 2 or more hours, followed by normal maintenance therapy. IM route not recommended, except when other methods of administration are not available.

Infants and children under 10 years, digitalization (all routes), 0.01 – 0.02 mg/kg body weight repeated six hourly until therapeutic result is obtained, usually after 2– 4 doses.

Maintenance, 0.01 – 0.02 mg/kg body weight daily in single or divided doses.