The necessity and safety of using favipiravir in the treatment of adult patients with mild COVID-19

Objective. To provide evidence for the necessity and safety of using favipiravir for the treatment of adult patients with non-severe forms of COVID-19. Subjects and methods. Of the 168 study participants, 163 received at least one dose of the test drug or the comparator: 108 patients received etiotropic therapy with favipiravir (experimental group), 55 were treated with umifenovir or hydroxychloroquine (comparison group). The endpoints of the study were time to clinical improvement according to the WHO Ordinal Scale of Clinical Improvement, time to viral elimination and presence or absence of adverse events (AEs), directly caused by the applied drugs, as well as AEs severity. Results. AEs were reported in both groups. A short-term increase in the level of hepatic transaminases was most often observed in overall population. In the experimental group, the most common AE was hyperuricemia, which is an expected reaction that is managed by medication discontinuing and causes no long-term consequences. At the same time, higher rate of virus elimination was recorded in the favipiravir group: in 71.4% of participants in the experimental group vs. 57.1% in the comparison group (on Day 3 and in 81.2% vs. 67.9% on Day 5, respectively. Clinical improvement occurred 4 days earlier in the experimental group (p = 0.005). Conclusion. The use of etiotropic therapy for the treatment of COVID-19 at its early stages and in case of non-severe forms of the disease is reasonable, necessary, and reduces the risk of complications. The choice of favipiravir as an initial treatment is based on the fact that its use resulted in earlier elimination of SARS-CoV-2 virus and much earlier onset of clinical improvement (by 4 days) according to the WHO Ordinal Scale of Clinical Improvement, when compared to umifenovir or hydroxychloroquine. Evaluation of the safety profile of favipiravir revealed no serious AEs associated with its use. However, when prescribing the drug, it should be remembered that favipiravir is contraindicated for pregnant women due to its teratogenic effects on the fetus. In addition, both men and women should apply the additional contraceptive methods during the period of drug use and for the following 3 months.

SARS-CoV-2, SARS-CoV-2, viral infection, favipiravir, hydroxychloroquine, umifenovir, ARVI, hepatic transaminases, hyperuricemia