FAVIPIRAVIR New drug approved in India for COVID 19 Hope or Hype

BREAKING NEWS : Appears in most TV channels on June 20, 2020 which mentions Now we got medicine available to treat Novel Corona virus . Does it really cure COVID-19 and how far this is effective and in whom it really works ?? these are frequently asked questions about this drug.

Giving his note on the occasion, Dr. Raj Kiran, Consultant Rheumatologist, Hyderabad Rheumatology Centre shared his insights on the latest developments. Here are the excerpts from the interview.

What is Favipiravir ?

Favipiravir is an antiviral drug. First discovered by Toyama Chemical inc ( FujiFilm ) a Japanese company. This drug is available in Japan since 2014 under name Avigan which is mainly used to treat FLU which are not responsive to routine antiviral drugs . This drug is thought to be unsafe in pregnant women .

How does Favipiravir work ?

This drug acts by inhibiting an enzyme called RNA dependent RNA polymerase . Novel corona virus after entering into cell produce this enzyme and with its help it will start replicating (Multiplying)  . Favipiravir is designed to block this enzyme and hence preventing viral replication which further reduces viral load .

Is Favipiravir effective ?

Research on favipiravir is done in China and Japan in the month of February 2020 and Chinese found 91% clearance of virus in 4 to 5 days . Russia has approved this drug for use by the end of May 2020. But not yet officially approved in USA and UK . They feel there is still no clear evidence of this drug working . Nearly 18 Clinical trials are going on to find its efficacy in various countries

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Status of Favipiravir in India ?

Glenmark Pharmaceuticals limited received DCGI regulatory approval for oral Favipiravir for the treatment of mild to moderate COVID-19 as mentioned in their website on Jun 20. In their research they found this drug is effective between 20 to 90 years age group and can be given in patients with diabetes, hypertension and cardiac patients . It offers rapid reduction in viral load within 4 days  and provides faster symptomatic and radiological improvement. Favipiravir has shown clinical improvement of up to 88% in mild to moderate COVID-19 cases. The drug is to be prescribed by specialist who treats COVID-19 and FLU , it is currently available in 200mg strength .The recommended dose is 9 tablets morning and night on day 1 followed by 4 tabs morning and night for 14 days .

Have we got the cure and Is this a magic bullet against COVID 19?

Not Exactly , Most antivirals can be effective in early stages that is in first week of disease. In later stages of disease when disease progress to second and third weeks other complications like blood clot formation , hyper inflammation sets in . 80% patients recover after a week to 10 days , rest may develop complications in 2^nd and 3^rd week , these are all serious cases .  Favipiravir alone might not be effective at this stage we need to use medications like anticoagulants ( drugs which prevent clots ) steroids ( recent study on dexamethasone had shown improvement when used in sick cases ) Methyl prednisolone another steroid medications is also used at this stages. An anti rheumatic medicine called Actemra ( Tocilizumab ) an injection which is commonly used to treat rheumatoid arthritis and child hood arthritis works effectively in this stage . So Early detection and treatment is key . So many doctors feel anti viral drugs alone cannot be game changers in treating this disease .

Who can be benefitted with Favipiravir ?

Now that this drug had got approval in mild to moderate cases  favipiravir will be used in those cases . This is oral drug , Japanese researchers studied this drug by giving it to critically ill and sick patients via nasogastric tube ( a pipe placed thru nose and reaches stomach which is commonly used to feed patients who are sick and most often on ventilator , where another tube called endo tracheal tube is placed thru mouth to airways of lungs for oxygen supply ) the concentration in blood was found to be much lower than that of healthy patients who take this by mouth and at this concentration the drug may not have an effective antiviral properties . This can be one reason this drug may not be effective in sick patients and got approval for mild to moderate COVID-19 . Most of the patients with COVID-19 can improve with out specific treatment , In study done by Russia they found this drug clears virus in 4 days compared to 9 to 11 days in people who had not received this medicine .

DCGI has given approval for its restricted use , this drug is not for pregnant and feeding mothers and approved only in adults . Many can improve from COVID-19 with supportive therapies . So the expert doctor who is treating COVID-19 will decide whether you are eligible for this drug or not . Doctors can use COVID-19 prognostic tool to calculate the risk . It is to be given after consent from family members . DCGI says the surveillance of first 1000 patients is needed . So once doctors start using this drug they get more experience and can better judge who exactly can be befitted with this drug and for who it is not needed.

What can be side effects of Favipiravir ?

The product insert of Avigan ( Japanese favipiravir ) mentions side effects like increase in blood uric acid levels (4.7% ), diarrhea (4.7%) and reduced white cell counts and changes in liver function tests ( 1.8% ) .

What is the difference between Favipiravir and Remdesivir another anti viral medicine used to treat COVID-19?

The main difference is Favipiravir can be given orally,  one can take staying at home and Remidesivir needs to be given intravenous requiring hospital stay  . Remdesivir as on today  is approved only for compassionate use in India .

What about general precautions ?

As on today taking safety precautions stands on top priority . In any given time for any disease ‘prevention is better than cure “ . So never ever ignore hand sanitization , masks and physical distancing.

To conclude , now in our country we have an approved antiviral drug which has clear mechanism of action against novel corona virus and has decent efficacy . Japanese , Chinese , Russians had used quite effectively ,Many countries are about to launch in few days  and many are waiting for complete clinical trial data to come . There is hope , but the hype in news and forwarded whats App messages can prevail a sense of comfort in people feeling  we have a cure now and ignoring precautionary measures can push us towards complications .  In next few months we will know how far Favipiravir will be effective in curtailing COVID 19 .

Book Appointment: Dr. Raj Kiran, Consultant Rheumatologist, Hyderabad Rheumatology Centre

References

1.glenmarkpharma.com

2.Experimental Treatment with Favipiravir for COVID-19: An Open-Label Control Study doi.org/10.1016/j.eng.2020.03.007

3. Pharmacokinetics of Favipiravir in Critically Ill Patients with COVID-19  doi: 10.1111/CTS.12827

4. Russia Approves Flu Drug’s Use Against Covid-19 – WSJ

5. https://qxmd.com/calculate/calculator_731/covid-19-prognostic-tool