Dose of digoxin is NOT altered in ?
**Core Concept**
Digoxin is a cardiac glycoside used in the treatment of atrial fibrillation and heart failure. Its dose needs to be adjusted in patients with certain clinical conditions to avoid toxicity.
**Why the Correct Answer is Right**
The dose of digoxin is not altered in patients with renal failure because digoxin is excreted primarily through the kidneys. However, digoxin has a narrow therapeutic index, and its toxicity increases with age, hypokalemia, and hypercalcemia. In patients with renal failure, the dose of digoxin is adjusted based on serum levels rather than creatinine clearance.
**Why Each Wrong Option is Incorrect**
* **Option A:** Renal failure is not the correct answer because digoxin is excreted primarily through the kidneys, and its dose needs to be adjusted in patients with renal failure.
* **Option B:** This option is not provided, but it is likely that one of the options (e.g., hypokalemia, hypercalcemia, or age) is incorrect because digoxin toxicity increases with these conditions.
* **Option C:** This option is not provided, but it is likely that one of the options (e.g., hyperthyroidism or hypothyroidism) is incorrect because digoxin is contraindicated in these conditions.
* **Option D:** This option is not provided, but it is likely that one of the options (e.g., liver disease or electrolyte imbalance) is incorrect because digoxin is metabolized in the liver and its toxicity is increased by electrolyte imbalances.
**Clinical Pearl / High-Yield Fact**
Digoxin toxicity can be prevented by monitoring serum levels and adjusting the dose accordingly. A serum digoxin level of 1.5-2.5 ng/mL is considered therapeutic, while levels above 2.5 ng/mL are associated with toxicity.
**Correct Answer: A. Renal failure is not a contraindication for digoxin use, and the dose is adjusted based on serum levels rather than creatinine clearance.**