nukleosiinianalogeina

Nukleosiinianalogeina, known in English as nucleoside analogs, are a class of antiviral drugs and anticancer agents. They are structurally similar to the natural nucleosides that are the building blocks of DNA and RNA. This similarity allows them to be incorporated into the genetic material of viruses or rapidly dividing cells. Once incorporated, they can disrupt the normal replication process.

The mechanism of action typically involves one of two primary pathways. Firstly, they can act as chain terminators. After being phosphorylated by cellular or viral enzymes, they are added to a growing DNA or RNA strand. However, due to a modification in their structure, they prevent further nucleotides from being added, effectively halting the synthesis of the viral genome or cellular DNA. Secondly, some nucleoside analogs can inhibit key enzymes involved in viral replication, such as reverse transcriptase or DNA polymerase, without necessarily being incorporated into the genetic material themselves.

Nucleoside analogs are widely used in the treatment of various viral infections, including HIV/AIDS, hepatitis B and C, and herpes simplex virus. In cancer therapy, they are employed to interfere with the rapid proliferation of cancer cells. Examples include zidovudine (AZT) for HIV, lamivudine for HIV and hepatitis B, and gemcitabine for various cancers. While effective, they can also cause side effects due to their interference with normal cellular processes.