Antiviral Agents
- BP-S-6-Medicinal Chemistry III
- Mar 31
- 1 min read
Antiviral agents are medications used to treat viral infections by either inhibiting viral replication or modulating the host’s immune response.
These agents can be classified based on their target viruses or mode of action.
Classification of Antiviral Agents
1) Influenza A Virus Inhibitors
These agents inhibit viral replication by blocking the M2 protein, an ion channel essential for the viral lifecycle.
They are effective primarily against influenza A viruses.
Examples:
Amantadine Hydrochloride
Rimantadine Hydrochloride
2) Anti-Herpes Virus Agents
These agents work by inhibiting viral DNA synthesis in herpes viruses.
Examples:
Idoxuridine Trifluoride (used topically for herpetic keratitis)
Acyclovir
Ganciclovir
Mechanism of Action:
Idoxuridine is incorporated into viral DNA, disrupting replication.
Acyclovir & Ganciclovir are nucleoside analogs that, once phosphorylated, act as competitive inhibitors of viral DNA polymerase and function as chain terminators.
3) Reverse Transcriptase Inhibitors (Anti-HIV Agents)
These drugs inhibit the reverse transcriptase enzyme, which is critical in the lifecycle of retroviruses like HIV.
Examples:
Nucleoside Reverse Transcriptase Inhibitors (NRTIs):
Zidovudine
Didanosine
Zalcitabine
Lamivudine(Incorporated into viral DNA, causing chain termination.)
Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs):
Loviride
Delavirdine(Bind to reverse transcriptase, inducing conformational changes that inhibit activity.)
4) Protease Inhibitors (Anti-HIV Agents)
These agents inhibit HIV protease, preventing the cleavage of viral polyproteins into functional proteins, which is essential for viral maturation.
Examples:
Saquinavir
Indinavir
Ritonavir
5) Broad-Spectrum Antiviral Agents
These agents exhibit antiviral activity against a wide range of RNA and DNA viruses.
Example:
Ribavirin (Believed to inhibit viral RNA synthesis and modulate the host's immune response.)
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