NAPLEX (North American Pharmacist Licensure Examination) Practice Exam

Which medication is a common P-gp substrate?

1. Aspirin

2. Apixaban

3. Acetaminophen

4. Albuterol

The correct answer is: Apixaban

Apixaban is a common P-gp substrate because it is a prescription anticoagulant medication that is often used to prevent blood clots. P-gp, or P-glycoprotein, is a protein found in the body that helps transport substances across cell membranes. It also plays a role in the absorption, distribution, and elimination of medications. Aspirin and acetaminophen are not known to be P-gp substrates, meaning they are not affected by P-gp and do not significantly interact with it. Albuterol may interact with P-gp, but it is not considered a common P-gp substrate. Other medications such as digoxin, verapamil, and cyclosporine are also known to be P-gp substrates.