NAPLEX (North American Pharmacist Licensure Examination) Practice Exam

Which of the following drugs is known to increase iron absorption in CKD patients?

1. Ferric citrate

2. Aluminum hydroxide

3. Calcium carbonate

4. Lanthanum carbonate

The correct answer is: Ferric citrate

Ferric citrate is the correct answer because it is a phosphate binder that also acts as an iron-based phosphate binder. In CKD patients, especially those on dialysis, there is often a requirement for iron supplementation due to decreased erythropoietin production, frequent blood testing, and bleeding. Ferric citrate not only binds phosphate but also releases iron in the gut, increasing iron absorption. This dual action makes ferric citrate a suitable option for CKD patients who require both phosphate binding and iron supplementation. The other options, aluminum hydroxide, calcium carbonate, and lanthanum carbonate, do not have the same effect on increasing iron absorption in CKD patients. Aluminum hydroxide is an antacid and phosphate binder, while calcium carbonate is mainly used as an antacid and to treat calcium deficiencies. Lanthanum carbonate is another phosphate binder but does not have the additional benefit of increasing iron absorption seen with ferric citrate.