Management of digoxin poisoning

Despite a gradual decline in the clinical use of digitalis glycosides, digitalis toxicity continues to be responsible for substantial morbidity and mortality, particularly among the elderly. Digitalis poisoning may occur acutely, after intentional overdose, but is more often seen as the result of chronic intoxication among patients receiving digitalis therapy. Clinical findings in chronic digitalis poisoning are often subtle. The astute clinician will enquire about digitalis use in older patients with vague complaints and will not be dissuaded from considering digitalis toxicity in the face of a ‘therapeutic’ digitalis blood concentration. Two digitalis preparations continue to be used with frequency, depending on geography. Digoxin is the digitalis glycoside of choice in the USA, while digitoxin prevails in some parts of Europe. While the methods and half-lives of elimination differ markedly for these two substances, the approach to poisoning by either is similar. Advanced age, underlying cardiovascular disease, and severe hyperkalaemia represent poor prognostic factors in digitalis poisoning. Early administration of digitalis Fab fragments should be undertaken when life-threatening symptoms are present. Prophylactic therapy with reduced doses of Fab fragments should be strongly considered for less serious toxicity.