Influenza A<unk>  inhibits influenza activity by binding to amino acids in the M2 transmembrane channel and blocking proton transport across the M2 channel.<unk>  is believed to inhibit influenza's viral replication, possibly by preventing the uncoating of the virus's protective shells, which are the envelope and capsid. The M2 channel is known to be responsible for viral replication in the influenza virus. Genetic studies suggest that the virus M2 protein, an ion channel specified by virion M2 gene, plays an important role in the susceptibility of influenza A virus to inhibition by<unk> .<unk>  is bound inside the pore to amantadane specific amino acid binding sites with hydrogen binding and van der Waals interactions. The ammonium group (with neighboring water molecules) is positioned towards the C terminus with the amantadane group is positioned towards the N-terminus when bound inside the M2 pore. 350x350px Influenza resistance Resistance to<unk>  can occur as a result of amino acid substitutions at certain locations in the transmembrane region of M2. This prevents binding of the antiviral to the channel. The mutation S31N binding site with<unk>  is shown in the image to the left. It shows<unk>  binding into lumenal (top) or peripheral (bottom) binding sites with influenza M2 channel Serine 31 (gold) or Asparagine 31 (blue).<unk>  enantiomers interactions with M2<unk> , when sold as flumadine, is present as a racemic mixture; the R and S states are both present in the drug. Solid state NMR studies have shown that the R enantiomer has a stronger binding affinity to the M2 channel pore than the S-enantiomer of<unk> . Antiviral assay and electrophysiology studies show that there is no significant difference between the R and S enantiomers in binding affinity to amino acids in the M2 channel. Since the enantiomers have similar binding affinity, they also have similar ability to block the channel pore and work as an effective antiviral.<unk>  enantiomers R and S are pictured interacting with the M2 pore below to the right. This image shows that there is not a significant modeled difference between the R and S enantiomers. Parkinson's disease<unk> , like its antiviral cousin amantadine, possesses some NMDA antagonistic properties and is used as an antiparkinsonic drug (i.e., in the treatment of Parkinson's disease). However, in general, neither<unk>  nor amantadine is a preferred agent for this therapy and would be reserved for cases of the disease that are less responsive to front-line treatments. Other<unk>  is shown to be effective against other RNA-containing viruses. It can treat arboviruses like Saint Louis encephalitis and Sindbis. Other viruses that can be treated with<unk>  include respiratory synctial and parainfluenza viruses.<unk>  has also been shown to treat chronic hepatitis C.
Rimantadine
Amantadine
Quifenadine
Rupatadine
Alcaftadine
Loratadine
Oseltamivir
Tecovirimat