Favipiravir for treating COVID‐19

Is favipiravir useful in treating people with COVID‐19?

Key messages

Due to a lack of robust evidence, we are unclear if favipiravir provides any benefit in the treatment of people with coronavirus disease 2019 (COVID‐19) infections who do not require hospital admission, as well as those admitted to hospital.

Favipiravir might lead to mild side effects, but doesn't seem to cause major or severe side effects.

What is favipiravir?

Favipiravir is a medicine that can fight viruses. It is usually taken by mouth. Originally used for treating other viral infections, favipiravir has been suggested as a potential treatment for COVID‐19 as it prevents the reproduction of the virus. Medical regulators have approved favipiravir for emergency use to treat people with COVID‐19.

What did we want to find out?

We wanted to find out if favipiravir was better than no treatment, supportive treatment, or any other experimental antiviral treatment for people with COVID‐19, in terms of death, need for a breathing machine (mechanical ventilation), and other outcomes. We also wanted to find out if favipiravir was associated with any unwanted effects.

What did we do?

We searched for studies that compared favipiravir with no treatment, supportive treatment, or other antiviral treatment in people with COVID‐19 disease. We compared and summarized the results of the studies and rated our confidence in the evidence, based on factors such as study methods and sizes.

What did we find?

We found 25 relevant studies involving 5750 people. The studies were conducted in 13 different countries: Bahrain, Brazil, China, India, Iran, Kuwait, Malaysia, Mexico, Russia, Saudi Arabia, Thailand, the UK, and the USA. Most people were under 60 years old and had mild to moderate COVID‐19 symptoms.

What are the main results of our review?

• We do not know if favipiravir reduces the number of people who die from COVID‐19 when compared to dummy treatment, standard of care, or other antiviral medicines. The evidence supporting this is not very strong (derived from 11 studies involving 3459 people).

• It is also very unclear if favipiravir reduces the need for people to be put on ventilators compared to a dummy treatment or any other antiviral treatments (derived from 8 studies involving 1383 people).

• In people with mild symptoms, using favipiravir may not reduce the likelihood of needing hospitalization, but more research is needed to be sure (derived from 4 studies involving 670 people).

• Favipiravir has an unclear effect on the time it takes for people to improve, as defined by a reduction in their illness severity (derived from 4 studies involving 721 people).

• Favipiravir seems to make very little difference in reducing the need for treatment with oxygen, compared to a dummy treatment or other antiviral treatment (derived from 2 studies involving 543 people).

• Favipiravir might lead to mild side effects (derived from 18 studies involving 4699 people) but doesn't seem to cause major or severe side effects (derived from 12 studies involving 3317 people).

What are the limitations of the evidence?

Our confidence in the evidence for using favipiravir is limited because people in the studies had different disease severities and the studies were of varying sizes and had inconsistent results.

How up to date is the review?

The review considered evidence up to 18 July 2023.