Side effects

Old patients are especially at risk of developing digoxin toxicity and therefore should be commenced on a low dose. There is an increased risk of toxicity in hypokalaemia and renal failure. Blood levels should be measured regularly.

Possible side effects include:

• arrhythmia: the most common arrhythmias are ventricular extrasystoles, ventricular bigemny / trigemny and atrial tachycardia with complete heart block
• anorexia, nausea and vomiting and occasionally, diarrhoea
• confusion especially in the elderly
• yellow vision, blurred vision and photophobia
• gynaecomastia

If patient becomes toxic then stop digoxin, treat any arrhythmias and check potassium. Secretion of digoxin can be increased by using digoxin-specific antibodies.