NAPLEX (North American Pharmacist Licensure Examination) Practice Exam

Pyrimidine analog antimetabolites work by inhibiting pyrimidine synthesis. They function by interfering with the synthesis of pyrimidine nucleotides, essential building blocks of DNA and RNA. In contrast, the other options (A, C, D) do not directly inhibit pyrimidine synthesis. Folate antimetabolites (choice A) disrupt the synthesis of purine nucleotides by blocking folate metabolism. Platinum-based compounds (choice C) bind to DNA to form cross-links, disrupting DNA function. Taxanes (choice D) work by interfering with microtubule function during cell division.