Difficulty: Medium
Average Score: 68%
Simulated
A client with a organ transplant has been placed on methotrexate (Rheumatrex). Which of the following mechanism of actions below describes this medication?
Correct answer
B
Rationale
The correct answer is B: Inhibits replication by blocking folic acid synthesis. Methotrexate works by inhibiting dihydrofolate reductase, an enzyme involved in the synthesis of folic acid, which is essential for DNA replication. By blocking this enzyme, methotrexate interferes with the production of DNA and RNA, leading to the suppression of cell proliferation. This mechanism makes it effective in treating conditions like autoimmune diseases and cancer. Choices A, C, and D are incorrect because methotrexate does not directly target helper T cells, prevent DNA and RNA synthesis, or act as an estrogen blocker.