Question

A patient is on digoxin therapy with some concomitant medications. At presentation, the patient develops atrial fibrillation with control ventricular rate & his serum digoxin raised from his previous value. Which of the following medication have enhanced digoxin toxicity?

• A. Atenolol
• B. Clarithromycin
• C. KCL
• D. Triamterene

Answer 1

The Correct Option is B

In this scenario, we are identifying which medication among the options can enhance digoxin toxicity when taken concomitantly. Digoxin is a cardiac glycoside used to treat heart conditions like atrial fibrillation. Enhanced toxicity can occur due to increased serum digoxin levels which can lead to serious side effects like nausea, dizziness, and cardiac arrhythmias. The options are:

• Atenolol
• Clarithromycin
• KCL
• Triamterene

Among these, Clarithromycin is known to increase digoxin levels by inhibiting the p-glycoprotein in the intestines and renal tubules. This inhibition reduces digoxin clearance and increases its bioavailability, potentially leading to toxicity.

Let's examine each option:

1. Atenolol is a beta-blocker that does not interact with digoxin in a manner that increases its concentration.
2. Clarithromycin is a macrolide antibiotic that, as stated, can inhibit p-glycoprotein and cause higher digoxin serum levels, increasing toxicity risks.
3. KCL (potassium chloride) is used to increase potassium levels; it does not directly influence digoxin levels but rather impacts its effects as hypokalemia can increase the risk of digoxin toxicity.
4. Triamterene is a potassium-sparing diuretic; it does not cause increased serum levels of digoxin directly.

Therefore, the medication enhancing digoxin toxicity through increased serum levels is Clarithromycin.