Ribavirin is a synthetic nucleoside analogue, which was first discovered and developed in 1970 by researchers from the International Chemical & Nuclear Corporation (ICN), today known as Valeant Pharmaceuticals. Ribavirin was initially approved for use in humans to treat pediatric respiratory syncytial virus infections (RSV). In cell cultures the inhibitory activity of ribavirin for RSV is selective. The mechanism of action is unknown. Reversal of the in vitro antiviral activity by guanosine or xanthosine suggests ribavirin may act as an analogue of these cellular metabolites. There were no other significant advancements in the treatment of hepatitis C until 1998, when the combination of ribavirin and interferon-alpha gained approval. Clinically, ribavirin showed a small, additive antiviral effect in combination with interferon, but its main effect was dose-dependent prevention of virological relapse. The mechanism by which the combination of ribavirin and an interferon product exerts its effects against the hepatitis C virus has not been fully established. However, it could be thorough the inhibition of inosine monophosphate dehydrogenase (IMPDH), which is the key step in de novo guanine synthesis, a requirement for viral replication.

AM-679 is a drug that acts as a moderately potent agonist for the cannabinoid receptors. AM-679 is a 5-lipoxygenase-activating protein inhibitor. AM-679, found in Italy for the first time, but also identified during a seizure made by Hungarian authorities, almost concurrent with the Italian seizure.

TMC-353121, a small substituted benzimidazole RSV fusion inhibitor, has been developed by molecular modeling of the precursor molecule JNJ-2408068. It maintains high activity (pEC50 9.9) and low cytotoxicity, while presenting a shorter half-life in the lung (lung t1/2 25 h). TMC-353121 binds to an intermediate conformation of F. Binding of TMC353121 stabilizes the interaction of HR1 and HR2 in an alternate conformation of the 6HB, in which direct binding interactions are formed between TMC-353121 and both HR1 and HR2. Rather than completely preventing 6HB formation, data indicate that TMC-353121 inhibits fusion by causing a local disturbance of the natural 6HB conformation. TMC-353121 is a novel potent antiviral drug, in vivo reducing RSV replication and inhibiting consequential lung inflammation, with a great potential for further clinical development.

AM-679 is a drug that acts as a moderately potent agonist for the cannabinoid receptors. AM-679 is a 5-lipoxygenase-activating protein inhibitor. AM-679, found in Italy for the first time, but also identified during a seizure made by Hungarian authorities, almost concurrent with the Italian seizure.