Which drug inhibits DNA synthesis? 

There are several drugs that inhibit DNA synthesis. These drugs can be classified into different categories based on their mechanism of action.

One class of drugs that inhibits DNA synthesis is antimetabolites. These drugs mimic the structure of essential metabolic molecules, such as nucleic acids and proteins, and interfere with their function. Examples of antimetabolites that inhibit DNA synthesis include:

• Methotrexate: This drug inhibits the enzyme dihydrofolate reductase, which is involved in the synthesis of thymidine, one of the building blocks of DNA.
• Azathioprine: This drug inhibits the enzyme inosine monophosphate dehydrogenase, which is involved in the synthesis of guanosine, another building block of DNA.
• Cytarabine: This drug inhibits the enzyme ribonucleotide reductase, which is involved in the synthesis of deoxyribonucleotides, the precursors to DNA.

Other drugs that inhibit DNA synthesis include:

• Cisplatin: This drug forms covalent bonds with DNA, causing DNA strands to cross-link and preventing DNA synthesis.
• Bleomycin: This drug generates reactive oxygen species that damage DNA, leading to DNA strand breaks and inhibiting DNA synthesis.
• Doxorubicin: This drug intercalates into DNA and causes DNA damage, leading to DNA strand breaks and inhibiting DNA synthesis.

It is important to note that these drugs can have serious side effects, and their use is typically limited to specific medical conditions. They should only be used under the supervision of a healthcare professional.