The Mechanism of Action: How Favipiravir 400mg Combats RNA Viruses

05/07/2025

 

What are Favipiravir 400mg tablets?

Favipiravir 400mg tablets are antiviral medications that are primarily used for the treatment of various strains of influenza virus. It has also been used for the treatment of other pathogenic viral infections, such as the coronavirus in the early days of the pandemic when other medications were ineffective and even the ebolavirus. This medication primarily does the job of limiting the replication of the virus in the human body. It does so by shutting down a specific mechanism of replication in the virus (you will read about it later in the blog). It inhibits the function of RNA polymerase within the viral cells, which lowers the load for the immune system so that it can clear out the virus more easily.

How is Favipiravir’s Mechanism of Action Different from Other Antivirals?

There are many stages of viral DNA replication and infection that can be limited. Many antivirals rely on determining the entry of viral genetic material into the host cells by blocking attachment to the host cells. Some other antivirals block the necessary pathways for the viral DNA to join with the host DNA (it is an integral part of viral replication). Some other antivirals inhibit the uncoating of viral DNA altogether.

Favipiravir, however, works by inhibiting the RNA polymerase. RNA Polymerase is an enzyme that generates and replicates the genetic code of the virus, which helps in the further proliferation of the virus. Favipiravir breaks down into its active component inside the cell and blocks the functioning of this enzyme (RNA-dependent RNA Polymerase), which limits the multiplication of viral RNA.

What are the Side Effects of Using Favipiravir 400mg Tablets?

The Favipiravir 400mg Generic Pill does not have a lot of side effects apart from the usual nausea, vomiting, diarrhea, and abdominal pain.

Other serious side effects include a reduced neutrophil count. This can be contraindicative of the actual use of the medicine as we need our immune system to work at full capacity to fend off viruses and other pathogens. A weakened immune system may cause further complications.

Favipiravir may also cause hyperuricemia, which essentially means that there is an increase in the levels of uric acid in the body. People who already have elevated uric acid levels or are suffering from gout should be cautious while using this medication.

What are Some Precautions You Need to Take While Using Favipiravir 400mg Tablets?

Favipiravir should not be used if you are pregnant or breastfeeding, as this medicine may harm the fetus. If you are a male using this medicine, you should use contraceptive methods such as a condom, as this medicine may also release sperm.

You should not use Favipiravir if you are allergic to any of the active or inactive substances present in the medicine. You should talk to your doctor about this if you are already allergic to any other antiviral medication.

Talk to your doctor if you are concerned about the side effects or any other precautions regarding the use of this medication.

How do Viruses Multiply in Our Bodies?

Viruses themselves are entities that carefully tread the line between living and non-living organisms. Scientists always debate whether they are alive or not. Let us follow the “life cycle” of a virus to better know how our body and antivirals deal with an infection.

It begins with the virus entering the body through any opening in the body, depending on the type of the virus. For example, the influenza virus spreads through droplets and the air.

Once the virus enters the body, it then tries to enter into its targeted cell. The virus then injects its DNA/ RNA/ genetic material into the targeted cell in the body. Once its genetic material enters the cell, it then blends and hides with the host’s DNA.

This DNA, when present in the host cell, hijacks the host cells and instructs it to produce more and more viral cells of its kind. Once the cell is filled with viral cells, the host cells burst and release more viral cells into the extracellular space in the body, where this cycle is repeated.

Antivirals usually stop one or multiple processes of cells and make them unable to replicate.

NOTE: this is a very simplified explanation of how a viral cell multiplies, not taking into account any of its technical components.

What did Clinical Studies Reveal about Favipiravir 400mg Tablets?

Favipiravir was used in the early COVID-19 pandemic stages, but there was not ample research to treat the SARS-COV-2 virus. However, there are many studies that show that this medication, in large doses, accelerates the decrease in virus numbers.

The first drug repurposing efforts were made in Japan, where this medicine was first approved for use in other drug-resistant cases for the treatment of viruses. During the COVID-19 pandemic, this drug was then sent into early testing in Russia and China, where there were clinical trials done on randomized low-risk COVID Patients. They received a high dose of oral Favipiravir.

Although this medication was used to treat COVID-19 patients in the beginning, as we studied more trials, we found that the evidence of its action was inconclusive. It was involved in the standard treatment protocol for COVID-19 in countries like Russia, Thailand, Japan, China, and India. Countries such as the US and the UK conducted more trials before incorporating it into the treatment protocol.

Conclusion

Viral infections are mostly considered to be harmless, and diseases such as the flu aren’t treated with antivirals unless absolutely necessary. Antivirals are used very scarcely as we do not want viruses to build resistance against them too easily. Favipiravir played an absolutely colossal role in the early treatment for COVID-19, reducing hospital stays and providing much-needed relief in the first wave of the pandemic when the severity of cases was relatively lower. Living in the era of modern medicine, we carry ways to treat or manage symptoms of almost all diseases known to mankind. The mortality rate currently is the lowest in forever in history, and life expectancy is at its highest. As modern medicine develops and flourishes more, we will find more and more treatments for diseases that seem untreatable in the current times.

FAQs:

1. What Is Favipiravir and How Does It Work Against RNA Viruses?

Favipiravir exhibits a different mechanism of action from other antiviral drugs. It works by inhibiting the replication of the viral genome. It does so by interacting with the genetic material of the virus and inactivating it through several hypothesized pathways.

2. Which Viruses Are Treated Using Favipiravir 400mg?

Favipiravir 400mg tablets are used to treat several strains of the influenza virus, as its mechanism of action is most suited to the rapidly mutating virus. In recent years, several trials have been proven to treat Ebola and COVID-19.

3. How Does Favipiravir Inhibit Viral Replication?

Favipiravir works by targeting RNA-dependent RNA polymerase (RdRp). It is hypothesized to work by inhibiting RNA polymerase (it is an enzyme that plays a function in the replication of genetic matter). This helps limit the replication of the virus and, therefore, limit proliferation. This made it easier for the immune system to tackle the virus.

4. Is Favipiravir Effective for COVID-19 and Other Emerging Viruses?

Favipiravir was an antiviral that was used extensively in hospitals during the coronavirus pandemic and has shown shortened hospital stays and reduced need for oxygen support in mild to moderate cases of the coronavirus. It may also be used in other emerging viruses due to its unique mechanism of action.

5. Are There Any Risks or Side Effects of Favipiravir 400mg?

One of the significant side effects that have commonly emerged in patients who were treated with Favipiravir is hyperuricemia (elevated uric acid levels). Therefore, this medication was dangerous to use in patients who have gout or any other condition that resulted in already high uric acid levels.