purine nucleoside analog (PYOOR-een NOO-klee-oh-side A-nuh-log)
A type of anticancer drug that is similar to a natural chemical compound called purine. Cells use purine to make the chemical building blocks of DNA and RNA. Purine nucleoside analogs may kill cells, including cancer cells, by blocking important enzymes needed to make DNA and RNA and by damaging DNA. Some purine nucleoside analogs are used to treat certain types of leukemia and lymphoma. Also called PNA.