Favipiravir Effects on the Control of Clinical Symptoms of Hospitalized COVID-19 Cases: An Experience with Iranian Formulated Dosage Form

Coronavirus disease -19 (COVID-19) pandemic, caused by SARS-CoV-2, has gradually spread worldwide, becoming a major public health event. This situation requires designing a novel antiviral agent against the SARS-CoV-2; however, this is time-consuming and the use of repurposed medicines may be promising. One such medicine is favipiravir, primarily introduced as an anti-influenza agent in east world. The aim of this study was to evaluate the efficacy and safety of favipiravir in comparison with lopinavir-ritonavir in SARS-CoV-2 infection. In this randomized clinical trial, 62 patients were recruited. These patients had bilateral pulmonary infiltration with peripheral oxygen saturation lower than 93%. The median time from symptoms onset to intervention initiation was seven days. Favipiravir was not available in the Iranian pharmaceutical market, and it was decided to formulate it at the research laboratory of School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran. The patients received favipiravir tablet at a dose of 1600 mg orally twice a day for day one and then 600 mg orally twice a day for days 2 to 6. In the second group, the patients received lopinavir-ritonavir combination tablet at a dose of 200/50 mg twice a day for seven days. Fever, cough, and dyspnea were improved significantly in favipiravir group in comparison with lopinavir-ritonavir group on days four and five. Mortality rate and ICU stay in both groups were similar, and there was no significant difference in this regard (P = 0.463 and P = 0.286, respectively). Chest X-ray improvement also was not significantly different between the two groups. Adverse drug reactions occurred in both groups, and impaired liver enzymes were the most frequent adverse effect. In conclusion, early administration of oral favipiravir may reduce the duration of clinical signs and symptoms in patients with COVID-19 and hospitalization period. The mortality rate also should be investigated in future clinical trials.