Zanamivir, mechanism

Wang MZ, Tai CY, Mendel DB (2002) Mechanism by which mutations at His274 alter sensitivity of influenza a vims N1 neuraminidase to oseltamivir carboxylate and zanamivir. Antimicrob... 

Fig. 3 Zanamivir , an antiviral drug which inhibits viral sialidases and below the mechanism of hydrolysis of sialosides with the transition state 4 mimed by Zanamivir .

Pharmacology The proposed mechanism of action of zanamivir is via inhibition of influenza virus neuraminidase with the possibility of alteration of virus particle aggregation and release. 

Mechanism of Action. Oseltamivir and zanamivir inhibit a specific enzyme (neuraminidase) that the influenza virus uses to complete its biosynthesis and release. By inhibiting this enzyme, these drugs impair a key step in viral replication, and reduce the ability of the virus to infect other respiratory cells. 

Oseltamivir and zanamivir are available for treatment of infections due to I influenza A and B. The mechanism of their antiviral action is inhibition of ... 

MECHANISMS OF ACTION AND RESISTANCE Zanamivir inhibits viral neuraminidase and... 

I Amantadine blocks the attachment, penetration, and uncoating of influenza virus A zanamivir and oseltamivir inhibit influenza viruses A and B neuraminidase, promoting viral clumping and decreasing the chance of penetration. Ribavirin becomes phosphorylated and inhibits IMP dehydrogenase and RNA polymerase. It is used to treat respiratory syncytial virus, influenza A and B, Lassa fever. Hantavirus, and as an adjunct to alpha-interferons in hepatitis C. The mechanisms, clinical uses, and side effects of these drugs are considered. 

Due to the transfer mechanism of TcTS analogous to those of sialidases [25] the prototype of sialidase inhibitors Neu5Ac2en 99 [57] was tested. Compound 99 as well as the potent influenza virus neuraminidase inhibitors zanamivir (Relenza, 100) and the active form of oseltamivir (Tamiflu, 101) with analogous structures of transition state were also of interest as potential inhibitors of TcTS. However, as determined for 99 the TcTS activity was inhibited with only Ki = 12.29 mM (Fig. 15) [33]. 

Figure 6.19 Mechanism of hydroiysis of neuraminidase and zanamivir as a transition-state analogue.

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