Cardiac Medicine Certification (CMC) Practice Exam

What is the most common electrolyte imbalance associated with diuretic use?

1. Hyperkalemia

2. Hypomagnesemia

3. Hypokalemia

4. Hypercalcemia

The correct answer is: Hypokalemia

Diuretics are medications that promote the excretion of urine and are commonly used in managing conditions such as hypertension, heart failure, and edema. One of the most significant effects of diuretics is their impact on electrolyte levels in the body, particularly potassium. Hypokalemia, or low potassium levels in the blood, is the most common electrolyte imbalance associated with diuretic use. This is particularly true for loop diuretics (like furosemide) and thiazide diuretics, which increase the renal excretion of potassium. As these diuretics promote diuresis, they lead to the loss of potassium alongside sodium and water, potentially resulting in symptoms like weakness, fatigue, muscle cramps, and cardiac arrhythmias when potassium levels drop significantly. While other electrolyte imbalances can occur with diuretics, such as hypomagnesemia due to the increased renal loss of magnesium or hyperkalemia, especially associated with potassium-sparing diuretics, hypokalemia remains the most frequently encountered problem. Therefore, understanding the risk of hypokalemia is crucial for healthcare providers managing patients on diuretics to monitor and address this potential complication effectively.