NAPLEX (North American Pharmacist Licensure Examination) Practice Exam

What mechanism of action does Rifampin have?

1. Cell Wall Inhibitor

2. Folic Acid Synthesis Inhibitor

3. Protein Synthesis Inhibitor

4. DNA/RNA Inhibitor

The correct answer is: DNA/RNA Inhibitor

Rifampin is a DNA/RNA inhibitor, which means it works by targeting the genetic material of a bacterial cell and either disrupting DNA replication or preventing the synthesis of RNA. This ultimately leads to the death or inhibition of bacterial growth. Option A, cell wall inhibitor, would typically imply a drug that targets the cell wall of bacteria, but Rifampin does not have this mechanism of action. Option B, folic acid synthesis inhibitor, would suggest a drug that interferes with the production of folic acid, an essential nutrient for bacteria. While Rifampin can indirectly affect folic acid synthesis, it is not its primary mechanism of action. Option C, protein synthesis inhibitor, would be a drug that interferes with the process of protein production in bacteria. Again, while Rifampin may have some effect on protein synthesis, it is not the main mechanism of action. Therefore, option D, DNA/RNA inhibitor, is the correct answer for Rifampin's mechanism of action.