This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Digoxin action is not affected in: 
Select and explain. 
A. Hepatic disease, B. Electrolyte disturbances, C. Renal failure, D. MI
A: Hepatic disease
Answer: A: Hepatic disease 
Explanation: Digoxin is eliminated mainly via excretion through kidney whereas digitoxin is metabolized by the liver. The dose of digoxin, therefore, does not require an adjustment in hepatic failure whereas it has to be reduced in renal failure. The arrhythmogenic dose of digitalis is reduced in MI. It should be used after MI only when CHF is accompanied with AF and rapid ventricular rate.
Hypokalemia, hypomagnesemia and hypercalcemia predisposes to digitalis toxicity.