Digoxin toxicity may result from the concurrent administration of digoxin with all drug EXCEPT
a. Quinidine b. Hydrochlorothiazidec. Triamterene
d. Furosemide
Ans. (C). Triamterene
Triamterene is a
potassium-sparing diuretic that may protect against diuretic-induced digoxin
toxicity. Di-goxin toxicity may be caused by drugs that increase serum digoxin
levels or increase the binding of digoxin to its receptor, the sodium-potassium
adenosine tnphosphatase (ATPase). Quinidine decreases digoxin volume of
distribution and clearance. Verapamil also decreases the clearance of digoxin.
Both drugs may thereby increase serum digoxin levels and precipitate digoxin
toxicity. Diuretics (e.g., hydrochlorothiazide, furosemide) may cause
hypokalemia and hypomagnesemia, both of which may predispose to cardiac
arrhythmias. Furthermore, hypokalemia increases di-goxin binding to
sodium-potassium ATPase.
