Question

Which of the following drugs act by inhibiting DNA replication ?

• A. 6 Mercaptopurine
• B. Actinomycin D
• C. Mitomycin C
• D. Asparaginase

Answer 1

The Correct Option is A

In pharmacology, understanding the mechanism of action of various drugs is crucial. When it comes to inhibiting DNA replication, certain drugs are designed to interfere with this process, thereby halting cell division and proliferation, which is particularly useful in cancer treatment. Let's evaluate the given options:

• 6 Mercaptopurine: This drug is an antimetabolite and works by incorporating itself into the DNA structure. It inhibits the enzyme involved in purine nucleotide synthesis, disrupting DNA replication and promoting apoptosis of rapidly dividing cells.
• Actinomycin D: This is a chemotherapy drug that intercalates between DNA bases, interfering with RNA synthesis, not directly with DNA replication.
• Mitomycin C: This drug acts as a cross-linking agent, which binds to DNA and inhibits both DNA replication and transcription, but its primary action is not described as simply inhibiting replication.
• Asparaginase: This enzyme-based drug reduces the availability of asparagine, an amino acid, which starves the cancer cells but does not directly inhibit DNA replication.

The correct answer is 6 Mercaptopurine, as it directly inhibits DNA replication by disrupting the synthesis of purine nucleotides, which are essential for DNA formation.