Viruses are acellular, intracellular obligatory parasites so the chemotherapeutic agents must enter the host's cell to attack the viruses. Besides, virus don't have complex structure or cell wall & membrane & they are only involved in few physiological activity other than replication. Therefore,there are limited antiviral agents & must antiviral agents interrupt the viral replication.
- Amantadine & Zanamivir( prevents attachment of Influenza virus to host cell membrane).
- Acyclovir & Ganciclovir ( They are incorporated into viral DNA during replication cycle of HSV & CMV).
- Anti-HIV drugs like Nevirapine( they binds & inhibits reverse transcriptase)
- Interferons: They are small glycoproteins cells exposed to interferon develop antiviral properties. ie interference of protein synthesis .