Antiviral Drugs (1 )

Definitions .
Classification of Antiviral drugs.
Features of Antiviral drugs.
Assessment .
Homework.
References .
Viruses are obligate intracellular parasites. They lack both a cell wall and a cell membrane, and they do not carry out metabolic processes.
Viruses use much of the host’s metabolic machinery, and few drugs are selective enough to prevent viral replication without injury to the infected host cells.

Therapy for viral diseases is complicated by the fact that the clinical symptoms appear late in the course of the disease, at a time when most of the virus particles have replicated. At this stage of viral infection, administration of drugs that block viral replication has limited effectiveness. However, some antiviral agents are useful as prophylactic agents.

I - Viral respiratory tract infections :
Treatments exist include influenza A and B and respiratory syncytial virus (RSV).
A.Neuraminidase inhibitors
The neuraminidase inhibitors oseltamivir and zanamivir are effective against both type A and type B influenza viruses.


Mechanism of action:
Oseltamivir and zanamivir selectively inhibit neuraminidase that is inserted into the host cell membrane for the purpose of releasing newly formed virions., thereby preventing the release of new virions and their spread from cell to cell.

Mechanism of action:
Oseltamivir and zanamivir selectively inhibit neuraminidase that is inserted into the host cell membrane for the purpose of releasing newly formed virions., thereby preventing the release of new virions and their spread from cell to cell.