digoxin and prednisolone

Prednisolone causes increased renal potassium excretion, leading to hypokalemia. Low serum potassium increases the sensitivity of the myocardium to digoxin by reducing the competition between potassium and digoxin at the Na+/K+ ATPase pump, thereby increasing the risk of digoxin toxicity.

Patients may develop signs of digoxin toxicity, including nausea, vomiting, visual disturbances, and cardiac arrhythmias such as ventricular ectopy, heart block, or atrial fibrillation. The risk is particularly high in patients with underlying cardiac disease or those on diuretics.

Monitor serum potassium, digoxin levels, and ECG at baseline and periodically during concurrent therapy. Correct any hypokalemia promptly. Consider potassium-sparing diuretics or potassium supplementation if needed. Adjust digoxin dose based on clinical response and levels. In patients with hypokalemia, digoxin toxicity may occur even at therapeutic digoxin levels.

Well-established; supported by clinical experience and pharmacodynamic principles. Corticosteroid-induced hypokalemia is a known risk factor for digoxin toxicity.