|
Use in Patients with Electrolyte Disorders: In patients with hypokalemia or hypomagnesemia, toxicity may occur despite serum digoxin concentrations below 2 ng/ mL, because potassium or magnesium depletion sensitizes the myocardium to digoxin. Therefore, it is desirable to maintain normal serum potassium and magnesium concentrations in patients being treated with digoxin. Deficiencies of these electrolytes may result from malnutrition, diarrhea, or pro-longed vomiting, as well as the use of the following drugs or proce-dures: diuretics, amphotericin B, corticosteroids, antacids, dialysis, and mechanical suction of gastrointestinal secretions. Hypercalcemia from any cause predisposes the patient to digital-is toxicity. Calcium, particularly when administered rapidly by the intravenous route, may produce serious arrhythmias in digitalized patients. On the other hand, hypocalcemia can nullify the effects of digoxin in humans; thus, digoxin may be ineffective until serum cal-cium is restored to normal. These interactions are related to the fact that digoxin affects contractility and excitability of the heart in a manner similar to that of calcium. Text Continues Below
Use in Thyroid Disorders and Hypermetabolic States Hypothyroidism may reduce the requirements for digoxin. Heart failure and/ or atrial arrhythmias resulting from hypermetabolic or hyperdynamic states (e. g., hyperthyroidism, hypoxia, or arteriovenous shunt) are best treat-ed by addressing the underlying condition. Atrial arrhythmias associ-ated with hypermetabolic states are particularly resistant to digoxin treatment. Care must be taken to avoid toxicity if digoxin is used. Use in Patients with Acute Myocardial Infarction: Digoxin should be used with caution in patients with acute myocardial infarction. The use of inotropic drugs in some patients in this setting may result in undesirable increases in myocardial oxygen demand and ischemia. Page: << Prev | 1 | 2 | 3 | Next >>
|
.gif)
