American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the typical treatment for Type 1 Distal Renal Tubular Acidosis?

1. Thiazide diuretics alone

2. Potassium-sparing diuretics

3. Potassium citrate

4. Sodium bicarbonate only

The correct answer is: Potassium citrate

Type 1 Distal Renal Tubular Acidosis (dRTA) is characterized by the kidney's inability to adequately excrete hydrogen ions, leading to a condition of metabolic acidosis and the potential for skeletal and dental issues due to the effects on calcium metabolism. The primary focus of treatment is to correct the metabolic acidosis and improve the acid-base balance in the body. Potassium citrate is often chosen as the typical treatment because it serves a dual purpose. First, it helps to neutralize the excess acid in the body when metabolized to bicarbonate. Second, it provides potassium, which can be beneficial since patients with type 1 dRTA often have hypokalemia due to renal loss of potassium. By using potassium citrate, patients can achieve improved bicarbonate levels and maintain appropriate serum potassium levels, addressing both the acidosis and potassium imbalance. Other treatment options listed are not suitable as standalone therapies for this condition. Thiazide diuretics can lead to further potassium loss, potentially exacerbating hypokalemia. Potassium-sparing diuretics may not provide sufficient correction of the metabolic acidosis and are generally not used as a primary treatment. Sodium bicarbonate could be used to treat acidosis, but it doesn't address potassium levels