American Board of Internal Medicine (ABIM) Certification Practice Exam

What is an effective management strategy for uric acid nephrolithiasis?

1. Dietary potassium restriction

2. Increased calcium intake

3. Maintaining adequate urine output and urine alkalinization

4. Administration of loop diuretics

The correct answer is: Maintaining adequate urine output and urine alkalinization

Maintaining adequate urine output and urine alkalinization is a well-established and effective management strategy for uric acid nephrolithiasis, which refers to the formation of kidney stones primarily composed of uric acid. Uric acid stones tend to form in acidic urine; therefore, the primary goal in managing this condition is to create a more alkaline environment in the urine. By alkalinizing the urine, typically achieved through the use of medications such as potassium citrate, urinary pH can be increased, which helps dissolve uric acid stones and prevents further stone formation. Additionally, ensuring adequate urine output is crucial as it decreases the concentration of stone-forming substances in the urine, thereby reducing the risk of stone formation. This approach addresses both immediate concerns regarding existing stones by promoting dissolution and preventing future episodes. In contrast to dietary restrictions on potassium or increased calcium intake—strategies that might not specifically target the underlying issue of uric acid crystallization—maintaining adequate urine output and alkalinizing urine are directly aimed at reducing uric acid levels and mitigating the risk of stone formation. Consequently, this management strategy is instrumental in the effective treatment and prevention of uric acid nephrolithiasis.