Which factor increases the risk of digoxin toxicity in older adults?

Which factor increases the risk of digoxin toxicity in older adults?

• A. Decreased liver and renal function
• B. Increased liver function
• C. Higher magnesium levels
• D. Lower risk due to age

Answer: (A)

Digoxin has a very narrow therapeutic window and is cleared mainly by the kidneys. In older adults, renal function often declines, so digoxin clearance decreases. This leads to higher circulating levels and a higher risk of toxicity, which can present with nausea, fatigue, confusion, and potentially dangerous heart rhythm changes. While liver function can influence some drugs, digoxin relies less on hepatic metabolism, so reduced liver function isn’t the primary driver. Higher magnesium levels aren’t the main predictor of digoxin toxicity, and aging itself isn’t protective—risk increases because renal function tends to worsen with age.

Digoxin has a very narrow therapeutic window and is cleared mainly by the kidneys. In older adults, renal function often declines, so digoxin clearance decreases. This leads to higher circulating levels and a higher risk of toxicity, which can present with nausea, fatigue, confusion, and potentially dangerous heart rhythm changes. While liver function can influence some drugs, digoxin relies less on hepatic metabolism, so reduced liver function isn’t the primary driver. Higher magnesium levels aren’t the main predictor of digoxin toxicity, and aging itself isn’t protective—risk increases because renal function tends to worsen with age.