Which compound is an example of an antimetabolite drug?

Which compound is an example of an antimetabolite drug?

• A. 6-mercaptopurine
• B. Penicillin
• C. Vancomycin
• D. Ciprofloxacin

Answer: (A)

Antimetabolites mimic the cell’s normal substrates and disrupt nucleotide synthesis or incorporation into nucleic acids. 6-mercaptopurine is a purine analog that, once activated inside the cell, blocks de novo purine synthesis and can be incorporated into DNA and RNA, leading to cytotoxic effects in rapidly dividing cells. This is why it’s classified as an antimetabolite and used in treating certain leukemias and other conditions. The other drugs don’t fit this mechanism: penicillin and vancomycin inhibit bacterial cell wall synthesis, and ciprofloxacin inhibits DNA gyrase/topoisomerase, not metabolic substrate pathways.

Antimetabolites mimic the cell’s normal substrates and disrupt nucleotide synthesis or incorporation into nucleic acids. 6-mercaptopurine is a purine analog that, once activated inside the cell, blocks de novo purine synthesis and can be incorporated into DNA and RNA, leading to cytotoxic effects in rapidly dividing cells. This is why it’s classified as an antimetabolite and used in treating certain leukemias and other conditions. The other drugs don’t fit this mechanism: penicillin and vancomycin inhibit bacterial cell wall synthesis, and ciprofloxacin inhibits DNA gyrase/topoisomerase, not metabolic substrate pathways.