Favipiravir (Avigan) for the Treatment of Covid-19 infection

Favipiravir (Avigan)

Favipiravir (Avigan) is an antiviral agent that was accidentally discovered at Research Laboratories of Toyama Chemical Co., Ltd.

It is a potent inhibitor of influenza virus RNA polymerase. Although, primarily being investigated for the treatment of viral influenza infection, it has a broad spectrum of activity against many viral pathogens.

The recent outbreak of the deadly virus COVID-19 has compelled scientists to come up with a solution.

While the role of Remdesivir, chloroquine, and Lopinavir/ritonavir in the treatment of the COVID-19 is being evaluated, Favirpiravir is thought to be another potential drug for the treatment and prevention of the outbreak.

In fact, Favipiravir is the first approved drug in the fight against COVID-19 and China has already started manufacturing it on a larger scale.

Recently, the Massachusett General Hospital published guidelines for the treatment of Coronavirus. However, Favipiravir has not been mentioned in these guidelines.

What is Favipiravir?

Favipiravir is a novel broad-spectrum antiviral drug that has potent antiviral activity. It inhibits the viral RNA polymerase.

It is effective against all the subtypes of influenza strains including those sensitive and resistant to the neuraminidase and M2 inhibitors.

It is a prodrug that is activated intracellularly to Favipiravir-RTP.

The spectrum of antiviral activity of Favipiravir:

It is active against the following viral pathogens [Ref]:

Orthomyxoviridae Influenza A (seasonal)

Influenza A (H5N1)

Influenza A (H1N1)pdm09

Influenza A (H7N9)

Influenza B

Influenza C

Bunyaviridae La Crosse

Punta Toro

Rift Valley fever

Sandfly fever



Crimean-Congo hemorrhagic fever

Prospect Hill

Severe fever thrombocytopenia syndrome

Arenaviridae Junin Pichinde Tacaribe Guanarito Machupo Lassa
Filoviridae Ebola
Rhabdoviridae Rabies
Paramyxoviridae Human metapneumovirus

Respiratory syncytial virus

Flaviviridae West Nile Yellow fever Zika virus
Togaviridae Western equine encephalitis Venezuelan equine encephalitis Eastern equine encephalitis Barmah forest Ross river Mayaro Chikungunya
Picornaviridae Polio Rhino Enterovirus 71
Caliciviridae Noro


It showed activity against influenza viruses that were resistant to both oseltamivir or zanamivir.

In animal studies, when administered at a dose of 30 mg/kg/day divided into two or four doses, there was a significant improvement seen in mice who received the drug compared to those who were not given the drug. None of the mice in the control group survived [Ref].

Compared to ribavirin, it was also found to be more potent in the treatment of viruses from the Bunyaviridae group. This group includes the deadly Lassa virus and Crimean Congo Hemorrhagic fever.

Another serious emerging viral infection is the “Severe fever with thrombocytopenia syndrome” (SFTS) that infects individuals residing primarily in Japan, Korea, and China. Cases are seen throughout the year, however, most cases occur in the winters.

Favipiravir was studied and found to be effective against the SFTS virus in vitro.

It has also been found to be effective in infections caused by the Zika virus and Ebola viruses.

Lastly, if administered in the presymptomatic phase of rabies virus infection at a dose of 30 mg/kg/day in divided doses, it was found to inhibit the viral activity and disease progression.

In conclusion:

Favipiravir is an attractive antiviral drug for the treatment of the COVID-19 infection that is associated with a high mortality rate.

It may also be used in the treatment of other deadly viral infections such as Ebola, Zika, and Rabies virus infections.


    • Sorry sir,
      I wish I could have it. I would have distributed it freely to all the affected individuals.
      This is not an e-commerce site.
      I just intend to share medical knowledge.

  1. It is worth a try. As long as any side effects are looked at closely vis a vis the patients health history of course.
    It would be good to see reports of this being used and all outcomes.

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