Antiviral agents are used to inhibit production of viruses that cause disease. Most antiviral agents are only effective while the virus is replicating.
It is difficult to find medicines that are selective for the virus as viruses share most of the metabolic processes of the host cell. However, some enzymes are only present in viruses and these are potential targets for antiviral drugs.

Drug classes:

• adamantane antivirals
• antiviral boosters
• antiviral combinations
• antiviral interferons
• chemokine receptor antagonist
• integrase strand transfer inhibitor
• miscellaneous antivirals
• neuraminidase inhibitors
• NNRTIs
• NS5A inhibitors
• nucleoside reverse transcriptase inhibitors (NRTIs)
• protease inhibitors
• purine nucleosides