Certification of Pharmacy Technicians (ExCPT) Practice Exam

Which diuretic can potentially cause hypokalemia?

1. Spironolactone

2. Triamterene

3. Hydrochlorothiazide

4. Amlodipine

The correct answer is: Hydrochlorothiazide

Hydrochlorothiazide is a thiazide diuretic that can lead to hypokalemia as a side effect. Thiazide diuretics work by inhibiting sodium reabsorption in the distal convoluted tubules of the nephron, which results in increased excretion of water and electrolytes, including potassium. The loss of potassium can lead to lower than normal potassium levels in the blood, a condition known as hypokalemia, which can result in various health issues, including muscle weakness and cardiac arrhythmias. In contrast, spironolactone and triamterene are potassium-sparing diuretics that work to prevent potassium loss, helping to maintain potassium levels in the body. Amlodipine does not have a diuretic effect; it is a calcium channel blocker used primarily for hypertension and heart-related conditions. Thus, it does not cause changes in potassium levels related to diuretic use.