1. pregnant or possibly pregnant patients or lactating females 2. patients have moderate to severe or immediately life-threatening covid-19 3. major risk factor onset (obesity, diabetes, copd, hypertension) 4. patients with spo2 less than 95% without oxygen therapy 5. patients with severe hepatic impairment equivalent to grade c on child-pugh classification 6. patients with renal impairment requiring dialysis 7. patients with disturbed consciousness such as disturbed orientation 8. female patients who are woman of childbearing potential and unable to consent to use of dual contraception from the start of favipiravir administration to 30 days after the end of favipiravir administration. dual contraception is a combination of two of the following: barrier method of contraception: condoms (male or female) with orwithout a spermicidal agent, diaphragm or cervical cap with spermicide; iud; hormone-based contraceptive; tubal ligation 9. male patients whose are unable to consent to use of barrier method of contraception (condom) the start of favipiravir administration to 90 days after the end of favipiravir administration. male patients who are planning to donate sperm in 90 days after the start of favipiravir administration. 10. patients with hereditary xanthinuria 11. patient with severe uncontrolled hyperuricaemia 12. patients receiving immunosuppressants 13. patients who received interferon-alpha or drugs with reported antiviral activity against sars-cov- 2 (hydroxychloroquine sulfate, chloroquine phosphate, lopinavir-ritonavir combination, ciclesonide, nafamostat mesylate, camostat mesylate, remdesivir, etc.) within 72 hours or patients who receive forbidden concomitant medication 14. any medical condition that the examining physician deems unsuitable for the patient to participate in the study

1. pregnant or possibly pregnant patients or lactating females 2. patients have moderate to severe or immediately life-threatening covid-19 3. major risk factor onset (obesity, diabetes, copd, hypertension) 4. patients with spo2 less than 95% without oxygen therapy 5. patients with severe hepatic impairment equivalent to grade c on child-pugh classification 6. patients with renal impairment requiring dialysis 7. patients with disturbed consciousness such as disturbed orientation 8. female patients who are woman of childbearing potential and unable to consent to use of dual contraception from the start of favipiravir administration to 30 days after the end of favipiravir administration. dual contraception is a combination of two of the following: barrier method of contraception: condoms (male or female) with orwithout a spermicidal agent, diaphragm or cervical cap with spermicide; iud; hormone-based contraceptive; tubal ligation 9. male patients whose are unable to consent to use of barrier method of contraception (condom) the start of favipiravir administration to 90 days after the end of favipiravir administration. male patients who are planning to donate sperm in 90 days after the start of favipiravir administration. 10. patients with hereditary xanthinuria 11. patient with severe uncontrolled hyperuricaemia 12. patients receiving immunosuppressants 13. patients who received interferon-alpha or drugs with reported antiviral activity against sars-cov- 2 (hydroxychloroquine sulfate, chloroquine phosphate, lopinavir-ritonavir combination, ciclesonide, nafamostat mesylate, camostat mesylate, remdesivir, etc.) within 72 hours or patients who receive forbidden concomitant medication 14. any medical condition that the examining physician deems unsuitable for the patient to participate in the study

pregnant or possibly pregnant patients or lactating females patients have moderate to severe or immediately life-threatening covid-19 major risk factor onset (obesity, diabetes, copd, hypertension) patients with spo2 less than 95% without oxygen therapy patients with severe hepatic impairment equivalent to grade c on child-pugh classification patients with renal impairment requiring dialysis patients with disturbed consciousness such as disturbed orientation female patients who are woman of childbearing potential and unable to consent to use of dual contraception from the start of favipiravir administration to 30 days after the end of favipiravir administration. dual contraception is a combination of two of the following: barrier method of contraception: condoms (male or female) with orwithout a spermicidal agent, diaphragm or cervical cap with spermicide; iud; hormone-based contraceptive; tubal ligation male patients whose are unable to consent to use of barrier method of contraception (condom) the start of favipiravir administration to 90 days after the end of favipiravir administration. male patients who are planning to donate sperm in 90 days after the start of favipiravir administration. patients with hereditary xanthinuria patient with severe uncontrolled hyperuricaemia patients receiving immunosuppressants patients who received interferon-alpha or drugs with reported antiviral activity against sars-cov- 2 (hydroxychloroquine sulfate, chloroquine phosphate, lopinavir-ritonavir combination, ciclesonide, nafamostat mesylate, camostat mesylate, remdesivir, etc.) within 72 hours or patients who receive forbidden concomitant medication any medical condition that the examining physician deems unsuitable for the patient to participate in the study

pregnant or possibly pregnant patients or lactating females patients have moderate to severe or immediately life-threatening covid-19 major risk factor onset (obesity, diabetes, copd, hypertension) patients with spo2 less than 95% without oxygen therapy patients with severe hepatic impairment equivalent to grade c on child-pugh classification patients with renal impairment requiring dialysis patients with disturbed consciousness such as disturbed orientation female patients who are woman of childbearing potential and unable to consent to use of dual contraception from the start of favipiravir administration to 30 days after the end of favipiravir administration. dual contraception is a combination of two of the following: barrier method of contraception: condoms (male or female) with orwithout a spermicidal agent, diaphragm or cervical cap with spermicide; iud; hormone-based contraceptive; tubal ligation male patients whose are unable to consent to use of barrier method of contraception (condom) the start of favipiravir administration to 90 days after the end of favipiravir administration. male patients who are planning to donate sperm in 90 days after the start of favipiravir administration. patients with hereditary xanthinuria patient with severe uncontrolled hyperuricaemia patients receiving immunosuppressants patients who received interferon-alpha or drugs with reported antiviral activity against sars-cov- 2 (hydroxychloroquine sulfate, chloroquine phosphate, lopinavir-ritonavir combination, ciclesonide, nafamostat mesylate, camostat mesylate, remdesivir, etc.) within 72 hours or patients who receive forbidden concomitant medication any medical condition that the examining physician deems unsuitable for the patient to participate in the study

1. pregnant or possibly pregnant patients or lactating females 2. patients have moderate to severe or immediately life-threatening covid-19 3. major risk factor onset (obesity, diabetes, copd, hypertension) 4. patients with spo2 less than 95% without oxygen therapy 5. patients with severe hepatic impairment equivalent to grade c on child-pugh classification 6. patients with renal impairment requiring dialysis 7. patients with disturbed consciousness such as disturbed orientation 8. female patients who are woman of childbearing potential and unable to consent to use of dual contraception from the start of favipiravir administration to 30 days after the end of favipiravir administration. dual contraception is a combination of two of the following: barrier method of contraception: condoms (male or female) with orwithout a spermicidal agent, diaphragm or cervical cap with spermicide; iud; hormone-based contraceptive; tubal ligation 9. male patients whose are unable to consent to use of barrier method of contraception (condom) the start of favipiravir administration to 90 days after the end of favipiravir administration. male patients who are planning to donate sperm in 90 days after the start of favipiravir administration. 10. patients with hereditary xanthinuria 11. patient with severe uncontrolled hyperuricaemia 12. patients receiving immunosuppressants 13. patients who received interferon-alpha or drugs with reported antiviral activity against sars-cov- 2 (hydroxychloroquine sulfate, chloroquine phosphate, lopinavir-ritonavir combination, ciclesonide, nafamostat mesylate, camostat mesylate, remdesivir, etc.) within 72 hours or patients who receive forbidden concomitant medication 14. any medical condition that the examining physician deems unsuitable for the patient to participate in the study

1. pregnant or possibly pregnant patients or lactating females 2. patients have moderate to severe or immediately life-threatening covid-19 3. major risk factor onset (obesity, diabetes, copd, hypertension) 4. patients with spo2 less than 95% without oxygen therapy 5. patients with severe hepatic impairment equivalent to grade c on child-pugh classification 6. patients with renal impairment requiring dialysis 7. patients with disturbed consciousness such as disturbed orientation 8. female patients who are woman of childbearing potential and unable to consent to use of dual contraception from the start of favipiravir administration to 30 days after the end of favipiravir administration. dual contraception is a combination of two of the following: barrier method of contraception: condoms (male or female) with orwithout a spermicidal agent, diaphragm or cervical cap with spermicide; iud; hormone-based contraceptive; tubal ligation 9. male patients whose are unable to consent to use of barrier method of contraception (condom) the start of favipiravir administration to 90 days after the end of favipiravir administration. male patients who are planning to donate sperm in 90 days after the start of favipiravir administration. 10. patients with hereditary xanthinuria 11. patient with severe uncontrolled hyperuricaemia 12. patients receiving immunosuppressants 13. patients who received interferon-alpha or drugs with reported antiviral activity against sars-cov- 2 (hydroxychloroquine sulfate, chloroquine phosphate, lopinavir-ritonavir combination, ciclesonide, nafamostat mesylate, camostat mesylate, remdesivir, etc.) within 72 hours or patients who receive forbidden concomitant medication 14. any medical condition that the examining physician deems unsuitable for the patient to participate in the study