Digitalis toxicity

Abstract

Digitalis intoxication occurs in 8 to 22 percent of patients who receive the drug. Cardiac arrhythmias are the most important and one of the most common signs of digitalis intoxication occurring in 80 to 90 percent of patients presenting with digitalis intoxication. Gastrointestinal symptoms such as nausea and anorexia are often the earliest signs. Neurologic manifestations also may be present. Factors that may precipitate digitalis intoxication are hypokalemia, hypomagnesemia, hypercalcemia, renal insufficiency, anoxia, acute myocardial infarction, and hypothyroidism. Digitalis assays are helpful, but not diagnostic in themselves, in determining digitalis intoxication. Understanding of the basic pharmacology of digitalis preparations helps in the rationale of the treatment of digitalis intoxication. Basic therapy includes prompt discontinuance of the drug along with supportive measures; cardiac monitoring often is necessary. Aggressive management is necessary in more severe forms of digitalis intoxication when significant arrhythmias are present. Various agents such as potassium, diphenylhydantoin (Dilantin), beta adrenergic blocking agents, and lidocaine have been used with varying degrees of success in the treatment of digitalis intoxication.