nucleoside analogue

Nucleoside analogues are a range of antiviral products used to prevent viral replication in infected cells.

The most commonly used is Aciclovir, although its inclusion in this category is uncertain, as it contains only a partial nucleoside structure, as the sugar ring is replaced by an open-chain structure.

Function

These agents can be used against hepatitis B virus, herpes simplex, and HIV.

Once they are phosphorylated, they work as antimetabolites by being similar enough to nucleosides to be incorporated into growing DNA strands; but they act as chain terminators and stop viral DNA Polymerase. They are not specific to viral DNA and also affect mitochondrial DNA. Because of this they have side effects such as bone marrow supression.

There is a large family of nucleoside analogue reverse transcriptase inhibitors, because DNA production by reverse transcriptase is very different from normal human DNA replication, so it is possible to design nucleoside analogues that are preferentially incorporated by the former.

Less selective nucleoside analogues are used as chemotherapy agents to treat cancer.

Resistance

Resistance can develop quickly with as little as one mutation.^{[citation needed]} Mutations occur in the enzymes that phosphorylate the drug to activate it.

Examples

Nucleoside analogue drugs include:

• deoxyadenosine analogues
  • Didanosine
  • Vidarabine (chemotherapy)
• deoxycytidine analogues
  • Cytarabine (chemotherapy)
  • Emtricitabine
  • Lamivudine
  • Zalcitabine
• deoxyguanosine analogues
  • Abacavir
• (deoxy-)thymidine analogues
  • Stavudine
  • Zidovudine (Azidothymidine, or AZT)
• deoxyuridine analogues
  • Idoxuridine
  • Trifluridine

Related drugs are nucleobase analogues such as Aciclovir and nucleotide analogues.

See also

• For nucleoside analogues in biology, see Nucleic acid analogues

This antimicrobial-related article is a stub. You can help Wikipedia by expanding it. v • d • e