Comment
Author: Admin | 2025-04-28
Enzymes in order to be active. They have a very restricted spectrum of activity and act on specific targets only. Its classification is based on the mode of action they illustrate at the different stages of the virus.The virus life cycle is divided into five stages;First stage: is the attachment phase, in which the virus gets attached to the cell wall of the host is energy-dependent, and is based on receptor-ligand recognition.Drugs that inhibits attachment and penetration – Gamma globulins.Second stage: is penetration in which it enters inside the host. The mechanism of entry of viruses is quite different. In phage, the coat remains outside and the contents of the virion enter the host, and the envelope virus penetrates via fusing with the host membrane.Drugs that inhibit the uncoating phase - Amantadine, Rimantadine, and Interferons are the main drugs that act by blocking the viral membrane matrix protein M2 which functions as an ion channel and helps in the fusion of both the membranes. It is given in the treatment of Influenza A and reduces the duration of symptoms thus giving a speedy recovery.Third stage: is the uncoating of the virus and release of the infectious nucleic acid from the protein coat. This is a simultaneous activity with an uncoating phase as nucleic acid enters the host and the protein capsid remains outside.Drugs that inhibit third phase - DNA polymerase enzyme inhibitors such as Acyclovir, Gancyclovir, Famcyclovir, Cidofovir and RNA polymerase inhibitors like Zidovudine, Didanosine, Stavudine and Zalcitabine.• Acyclovir and its congeners act by inhibiting the DNA polymerase and inhibit the formation of viral DNA. It is given in the treatment of Genital Herpes simplex Virus infections.• Zidovudine inhibits the RNA-dependent DNA polymerase enzyme to block DNA synthesis. Initial drug of choice in AIDS patients with CD4 counts less than
Add Comment