One family of chemotherapeutic drugs called purine nucleoside antimetabolites is mostly utilized to treat autoimmune illnesses and different types of cancer. These substances interfere with the manufacture and operation of nucleic acids by resembling the structure of purine nucleosides, which are the building blocks of DNA and RNA. They cause cell death by interfering with the regular processes of protein synthesis and cell replication by integrating into DNA or RNA. The suppression of enzymes involved in purine nucleotide synthesis is one of the main ways that purine nucleoside antimetabolites work. One enzyme that is essential for converting ribonucleotides into deoxyribonucleotides—which are required for DNA replication—is ribonucleotide reductase, which these drugs have the ability to block. Furthermore, they could suppress the activity of adenosine deaminase and inosine monophosphate dehydrogenase, which would impede the production of nucleotides and the growth of cells. Important instances of purine nucleoside antimetabolites are medications like pentostatin, fludarabine, and cladribine. Multiple sclerosis and hairy cell leukemia are two prevalent conditions treated with cladribine. After being intracellularly phosphorylated to become an active triphosphate form, it integrates into DNA to cause strand breaks and apoptosis. On the other hand, fludarabine is used to treat non-Hodgkin's lymphoma and chronic lymphocytic leukemia (CLL). After being broken down into its active form, 2-fluoro-ara-ATP, it interferes with DNA synthesis and repair by inhibiting DNA polymerase, DNA primase, and ribonucleotide reductase. Another purine nucleoside antimetabolite called pentostatin is mostly used to treat hairy cell leukemia. It works by preventing adenosine deaminase from functioning, which causes deoxyadenosine triphosphate (dATP) to build up and becomes hazardous to lymphocytes, especially T-cells. Pentostatin is effective at inhibiting the growth of lymphocytes because of its selective toxicity.Purine nucleoside antimetabolites have an effect on quickly dividing cells, which can lead to substantial adverse effects despite their effectiveness. Myelosuppression is a common side effect that increases the risk of bleeding, anemia, and infection by decreasing blood cell formation. Additionally common are digestive disorders such diarrhea, vomiting, and nausea. Furthermore, prolonged use may depress the immune system, making a person more vulnerable to opportunistic infections. Purine nucleoside antimetabolite optimization is still being studied, with an emphasis on reducing adverse effects and increasing therapeutic efficacy. Combination therapy are a popular tactic to improve treatment outcomes, in which these compounds are utilized in addition to other chemotherapeutic medications. Furthermore, by customizing the usage of purine nucleoside antimetabolites to better match patient-specific responses, knowledge of the unique genetic and molecular profiles of malignancies can be gained.In summary, purine nucleoside antimetabolites cause cell death by interfering with DNA synthesis and function, which is a critical part of cancer therapy. However, their use needs to be carefully controlled to strike a balance between toxicity and efficacy, which emphasizes the significance of continuing research in this area.
