Why antifolate drugs are used in cancer chemotherapy?

Interaction of Chemotherapy and Radiation The antifolate, methotrexate, tightly binds dihydrofolate reductase (DHFR) thereby inhibiting folate metabolism. Through this inhibition, thymidylate synthesis is blocked, and thus, purine biosynthesis.

How do Antifolates work?

Some such as proguanil, pyrimethamine and trimethoprim selectively inhibit folate’s actions in microbial organisms such as bacteria, protozoa and fungi. The majority of antifolates work by inhibiting dihydrofolate reductase (DHFR).

Which drugs are antifolate?

Antifolates currently approved for cancer treatment include methotrexate and pralatrexated, inhibitors of dihydrofolate reductase, and pemetrexed that, in it polyglutamate forms, targets thymidylate synthase and AICARFT(5-aminoimidazole-4-carboxamide ribonucleotide transformylase).

Is methotrexate an antifolate?

Methotrexate is an antifolate and antimetabolite originally developed to treat malignancy. In the setting of RA, it is given at much lower doses than when given as an anticancer agent. The usual dose is 7.5 to 25 mg per week given as a single dose orally.

Does folic acid interfere with chemotherapy?

Folic acid can interfere with certain chemotherapy drugs.

What is the mechanism of action of methotrexate?

Mechanism of Action The inhibition of DHFR by folate antagonists (methotrexate) results in a deficiency in the cellular pools of thymidylate and purines and thus in a decrease in nucleic acid synthesis. Therefore, methotrexate interferes with DNA synthesis, repair, and cellular replication.

How does leucovorin help in a methotrexate overdose?

Leucovorin is in a class of medications called folic acid analogs. It works by protecting healthy cells from the effects of methotrexate or similar medications while allowing methotrexate to enter and kill cancer cells.

Which of the following is alkylating agent?

Some examples of alkylating agents are nitrogen mustards (chlorambucil and cyclophosphamide), cisplatin, nitrosoureas (carmustine, lomustine, and semustine), alkylsulfonates (busulfan), ethyleneimines (thiotepa), and triazines (dacarbazine).

Which of the following is an antimetabolite?

Some antimetabolites that are commonly used to treat cancer include: 6-mercaptopurine. fludarabine. 5-fluorouracil.

Is atovaquone an antifolate?

The proguanil-atovaquone combination has a synergistic effect, although atovaquone, acting on mitochondrial electron transport system, is not an antifolate drug and the mechanism of synergism is still poorly understood.