• Antiviral chemotherapy • Interferon • Gene therapy • Chinese Herbs
Antiviral chemotherapeutic Agents
• Antiviral drugs are available to treat only a few viral diseases.
• The reason for this is the fact that viral replication is so intimately associated with the host cell that any drug that interferes significantly with viral replication, is likely to be toxic to the host
Targets for chemotherapeutic agents
• Attachment to host cell • Uncoating –(amantadine) • Synthesis of viral mRNA-(interferon) • Translation of mRNA-(interferon) • Replication of viral RNA or DNA- (nucleoside anologues) • Maturation of new virus proteins-(protease inhibitors) • Budding , release
Diseases for which effective therapy is available
• AIDS: Zidovudine叠氮胸苷+ Lamivudine拉米夫定+ protease inhibitors • Influenza: Amantadine • Herpes simplex virus: Acyclovir • Varicella-Zoster virus: Acyclovir • Cytomegalovirus : Gancyclovir更昔洛韦, Foscarnet膦甲 酸
• Respiratory syncitial virus: Ribavirin利巴韦林
• Nucleotide analogues competes with normal nucleotide for incorporation into viral DNA or RNA.
• Direct antiviral effect ( prevents the infection of new cells) by a) degradation of viral mRNA, and b) inhibition of protein synthesis
• Enhancement of the specofic immuneresponse by increasing the expression of MHC class I molecules on the surface of infected cells, the interferons increase the opportunity for specifif cytotoxic T cells to recognise and kill infected cells
• Chronic hepatitis B and C virus