A team of scientists from the South Pest Central Hospital and the Semmelweis University, Hungary, have conducted an observational study to evaluate the efficacy of an anti-influenza medicine favipiravir in treating hospitalized coronavirus disease 2019 (COVID-19) patients. The study reveals that favipiravir does not affect disease progression and all-cause mortality. The study is currently available on the MedRxiv* preprint server.
Favipiravir with COVID-19 Blood Sample. Image Credit: Novikov Aleksey/Shutterstock.com
Since the emergence of the COVID-19 pandemic, many studies have been conducted to identify specific antiviral therapeutics against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative pathogen of COVID-19. Currently, in-hospital treatment of moderate or severe COVID-19 patients is carried out by repurposed antiviral medicines, in addition to standard-of-care.
Although some of these medicines are promising in terms of reducing the symptom severity, the majority fails to attenuate disease progression and mortality rate. Given the severe adversity of the current pandemic condition, it is of prime importance to identify antiviral medicines that are specifically efficacious against SARS-CoV-2.
In the current study, scientists aimed to evaluate the antiviral potency of favipiravir in treating hospitalized COVID-19 patients. Favipiravir is a derivative of pyrazinecarboxamide used to treat influenza patients in Japan.
Current study design
The study was conducted on confirmed COVID-19 patients who were admitted to a hospital in Hungary between March and July 2020. The patients were divided into two groups. The patients receiving favipiravir along with standard care were categorized as the favipiravir group.
The patients in the non-favipiravir group received other antiviral medicines including chloroquine, hydroxychloroquine, lopinavir/ritonavir, remdesivir, or oseltamivir, in addition to standard care.
Primarily, the scientists analyzed the effect of favipiravir on overall disease progression, which includes all-cause mortality, the requirement for mechanical ventilation, and the requirement for immunomodulatory therapy.
A total of 75 patients were enrolled in each study group. The baseline characteristics showed that patients receiving favipiravir had a higher prevalence of hypertension, chronic heart disease, diabetes, and chronic cerebral disease.
The scientists did not observe any statistically significant difference between the two study groups in terms of disease progression. Specifically, the all-cause mortality rate and the requirement for ventilation were similar in both the groups; however, the patients receiving favipiravir showed a higher requirement for immunomodulatory therapy.
Moreover, favipiravir-receiving patients took a longer time to get PCR-negative results and stayed longer in the hospital than the patients receiving other antiviral medicines.
Overall, the study findings reveal that favipiravir is not very effective in treating in-hospital COVID-19 patients. The drug exhibits similar effectiveness as other antiviral medicines in modulating the progression of COVID-19.
Previous studies on favipiravir use have shown contradicting results. Reports are showing that favipiravir causes faster recovery from COVID-19 symptoms, including fever and cough. However, the drug fails to improve the clinical recovery rate in COVID-19 patients.
In contrast, studies comparing the efficacy of favipiravir and lopinavir/ritonavir reveal that favipiravir significantly improves the chest imaging reports and causes faster clearance of SARS-CoV-2 in COVID-19 patients.
Overall, no report is so far available to establish the potency of favipiravir in treating COVID-19 patients.
Based on the current study findings and available literature, scientists believe that favipiravir should not be regarded as potential COVID-19 medicine and that more studies are required to clinically establish the efficacy of favipiravir.
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.