Antiviral Agents Flashcards
Parts of a virus
- Capsids are usually made up of proteins called protomers
Life cycle of a virus
Classification of drugs used against DNA viruses (3)
- Inhibitors of viral DNA polymerase
- Inhibitos of tubulin polymerization
- Antisense therapy
An antiviral drug that as a nucleoside-like structure and contains the same nucleic acid base as deoxyguanosine, but lacks the complete sugar ring. It specifically inhibits viral DNA polymerase and used in the treatment of infections due to herpes simplex 1 and 2 as well as varicella-zoster virus.
Acyclovir
- Converted to the active form by thymidine kinase (more active in infected cells)
- Bind to DNA polymerase and inhibit it
- Acts as chain terminator
Prodrugs and analogues of acyclovir
- Valacyclovir - L-valyl ester prodrug
- Desciclovir - produrg without the carbonyl group
- Ganciclovir - analogue w/ an extra hydroxymethylene group
Drug which is an analogue of deoxycytidine 5-monophosphate, where the sugar and phosphate groups have been replaced by an acyclic group and a phosphomethylene group.
Cidofovir
- For viruses without thymidine kinase (cannot phosphorylate initially)
- Phosphomethylene group instead of phosphate to resist hydrolysis
Drugs which, unlike acyclovir, are phosphorylated equally by viral and cellular thymidine kinase which result in increase side effects.
- Iodoxuridine
- Trifluridine
- Vidarabine
An analogue of deoxythymidine used in the treatment of herpes keratitis. The triphosphate form of this drug inhibits viral DNA polymerase as well as thymidilate synthetase.
Idoxuridine
(but Trifluridine is the DOC)
The purine counterpart of the pyridimine nucleoside cytarabine (ara-C).
Vidarabine
A plant product used in the treatment of genital warts caused by DNA virus papillomavirus. It inhibits tubulin polymerization.
Podophyllotoxin
(but Imiquimod is more effective)
Drug which consists of 21 nucleosides and a phosphothionate backbone. It is a DNA antisense molecule that blocks the translation of viral RNA and is used againts retinal inflammation caused by CMV in AIDS patients.
Fomivirsen
(an antisense DNA molecule)
HIV drug class which are prodrugs that are converted by enzymes to active triphosphates which act as enzyme inhibitors and chain terminators.
Nucleoside Reverse Transcriptase Inhibitor
- Zidovudine
- Didanosine
- Abacavir
- Lamivudine
Anti-HIV drug class which act as enzyme inhibitors by binding to an allosteric binding site.
Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTI)
- 1st gen - Nevirapine
- 2nd gen - Efavirenz
Anti-HIV drug class which are designed to act as transition state inhibitors.
Protease Inhibitors
A nucleoside reverse transcriptase inhibitor which is an analogue of deoxythmidine where the 3’hydroxyl group is replaced by an azido group (N3).
Zidovudine
Anti-HIV drug which contains inosine as the nucleic acid base present and is converted through a series of enzume reaction to 2’,3’-didoexyadenosine triphosphate which is the active drug.
Didanosine
Anti-HIV drug which is an analogue of deoxycytidine where the 3’ carbon is replaced by sulphur.
Lamivudine
The only guanosine analogue that is used against HIV infections and Hepatitis B.
Abacavir
A second generation non-nucleoside reverse transcriptase inhibitor that has a benzoxaxinone structure
Efavirenz
