1. where, in the opinion of the investigator, participation in this study will not be in the best interest of the subject, or any other circumstances that prevent the subject from participating in the study safely; 2. refractory nausea, vomiting, or chronic gastrointestinal disorders, inability to swallow the study drug or having undergone extensive bowel resection which may affect adequate absorption of favipiravir; 3. severe liver disease: underlying liver cirrhosis or alanine aminotransferase (alt)/aspartate aminotransferase (ast) elevated over 5 times the uln; 4. gout/history of gout or hyperuricemia (above the uln); 5. oxygen saturation (spo2)≤93% or arterial oxygen partial pressure (pao2)/ fraction of inspired o2 (fio2)≤300 mmhg; 6. known allergy or hypersensitivity to favipiravir; 7. known severe renal impairment \[creatinine clearance (cccl) \<30 ml/min\] or having received continuous renal replacement therapy, hemodialysis or peritoneal dialysis; cccl is to be calculated by the following cockcroft-gault formula only when the serum creatinine is\>1.5×uln 8. possibility of the subject being transferred to a non-study hospital within 72h; 9. pregnant or lactating women; 10. having used favipiravir or participated in any other interventional drug clinical study within 30 days prior to first dose of study drug. note: considering that covid-19 requires immediate treatment, absence of severe hepatic/renal disorders (e.g., cirrhosis, long-term dialysis) in the medical record can be used as an evidence for eligibility determination. it is recommended that hepatic function and creatinine be examined whenever possible.

1. where, in the opinion of the investigator, participation in this study will not be in the best interest of the subject, or any other circumstances that prevent the subject from participating in the study safely; 2. refractory nausea, vomiting, or chronic gastrointestinal disorders, inability to swallow the study drug or having undergone extensive bowel resection which may affect adequate absorption of favipiravir; 3. severe liver disease: underlying liver cirrhosis or alanine aminotransferase (alt)/aspartate aminotransferase (ast) elevated over 5 times the uln; 4. gout/history of gout or hyperuricemia (above the uln); 5. oxygen saturation (spo2)≤93% or arterial oxygen partial pressure (pao2)/ fraction of inspired o2 (fio2)≤300 mmhg; 6. known allergy or hypersensitivity to favipiravir; 7. known severe renal impairment \[creatinine clearance (cccl) \<30 ml/min\] or having received continuous renal replacement therapy, hemodialysis or peritoneal dialysis; cccl is to be calculated by the following cockcroft-gault formula only when the serum creatinine is\>1.5×uln 8. possibility of the subject being transferred to a non-study hospital within 72h; 9. pregnant or lactating women; 10. having used favipiravir or participated in any other interventional drug clinical study within 30 days prior to first dose of study drug. note: considering that covid-19 requires immediate treatment, absence of severe hepatic/renal disorders (e.g., cirrhosis, long-term dialysis) in the medical record can be used as an evidence for eligibility determination. it is recommended that hepatic function and creatinine be examined whenever possible.

where, in the opinion of the investigator, participation in this study will not be in the best interest of the subject, or any other circumstances that prevent the subject from participating in the study safely; refractory nausea, vomiting, or chronic gastrointestinal disorders, inability to swallow the study drug or having undergone extensive bowel resection which may affect adequate absorption of favipiravir; severe liver disease: underlying liver cirrhosis or alanine aminotransferase (alt)/aspartate aminotransferase (ast) elevated over 5 times the uln; gout/history of gout or hyperuricemia (above the uln); oxygen saturation (spo2)≤93% or arterial oxygen partial pressure (pao2)/ fraction of inspired o2 (fio2)≤300 mmhg; known allergy or hypersensitivity to favipiravir; known severe renal impairment [creatinine clearance (cccl) <30 ml/min] or having received continuous renal replacement therapy, hemodialysis or peritoneal dialysis; cccl is to be calculated by the following cockcroft-gault formula only when the serum creatinine is>1.5×uln possibility of the subject being transferred to a non-study hospital within 72h; pregnant or lactating women; having used favipiravir or participated in any other interventional drug clinical study within 30 days prior to first dose of study drug. note: considering that covid-19 requires immediate treatment, absence of severe hepatic/renal disorders (e.g., cirrhosis, long-term dialysis) in the medical record can be used as an evidence for eligibility determination. it is recommended that hepatic function and creatinine be examined whenever possible.

where, in the opinion of the investigator, participation in this study will not be in the best interest of the subject, or any other circumstances that prevent the subject from participating in the study safely; refractory nausea, vomiting, or chronic gastrointestinal disorders, inability to swallow the study drug or having undergone extensive bowel resection which may affect adequate absorption of favipiravir; severe liver disease: underlying liver cirrhosis or alanine aminotransferase (alt)/aspartate aminotransferase (ast) elevated over 5 times the uln; gout/history of gout or hyperuricemia (above the uln); oxygen saturation (spo2)≤93% or arterial oxygen partial pressure (pao2)/ fraction of inspired o2 (fio2)≤300 mmhg; known allergy or hypersensitivity to favipiravir; known severe renal impairment [creatinine clearance (cccl) <30 ml/min] or having received continuous renal replacement therapy, hemodialysis or peritoneal dialysis; cccl is to be calculated by the following cockcroft-gault formula only when the serum creatinine is>1.5×uln possibility of the subject being transferred to a non-study hospital within 72h; pregnant or lactating women; having used favipiravir or participated in any other interventional drug clinical study within 30 days prior to first dose of study drug. note: considering that covid-19 requires immediate treatment, absence of severe hepatic/renal disorders (e.g., cirrhosis, long-term dialysis) in the medical record can be used as an evidence for eligibility determination. it is recommended that hepatic function and creatinine be examined whenever possible.

1. where, in the opinion of the investigator, participation in this study will not be in the best interest of the subject, or any other circumstances that prevent the subject from participating in the study safely; 2. refractory nausea, vomiting, or chronic gastrointestinal disorders, inability to swallow the study drug or having undergone extensive bowel resection which may affect adequate absorption of favipiravir; 3. severe liver disease: underlying liver cirrhosis or alanine aminotransferase (alt)/aspartate aminotransferase (ast) elevated over 5 times the uln; 4. gout/history of gout or hyperuricemia (above the uln); 5. oxygen saturation (spo2)≤93% or arterial oxygen partial pressure (pao2)/ fraction of inspired o2 (fio2)≤300 mmhg; 6. known allergy or hypersensitivity to favipiravir; 7. known severe renal impairment [creatinine clearance (cccl) <30 ml/min] or having received continuous renal replacement therapy, hemodialysis or peritoneal dialysis; cccl is to be calculated by the following cockcroft-gault formula only when the serum creatinine is>1.5×uln 8. possibility of the subject being transferred to a non-study hospital within 72h; 9. pregnant or lactating women; 10. having used favipiravir or participated in any other interventional drug clinical study within 30 days prior to first dose of study drug. note: considering that covid-19 requires immediate treatment, absence of severe hepatic/renal disorders (e.g., cirrhosis, long-term dialysis) in the medical record can be used as an evidence for eligibility determination. it is recommended that hepatic function and creatinine be examined whenever possible.

1. where, in the opinion of the investigator, participation in this study will not be in the best interest of the subject, or any other circumstances that prevent the subject from participating in the study safely; 2. refractory nausea, vomiting, or chronic gastrointestinal disorders, inability to swallow the study drug or having undergone extensive bowel resection which may affect adequate absorption of favipiravir; 3. severe liver disease: underlying liver cirrhosis or alanine aminotransferase (alt)/aspartate aminotransferase (ast) elevated over 5 times the uln; 4. gout/history of gout or hyperuricemia (above the uln); 5. oxygen saturation (spo2)≤93% or arterial oxygen partial pressure (pao2)/ fraction of inspired o2 (fio2)≤300 mmhg; 6. known allergy or hypersensitivity to favipiravir; 7. known severe renal impairment [creatinine clearance (cccl) <30 ml/min] or having received continuous renal replacement therapy, hemodialysis or peritoneal dialysis; cccl is to be calculated by the following cockcroft-gault formula only when the serum creatinine is>1.5×uln 8. possibility of the subject being transferred to a non-study hospital within 72h; 9. pregnant or lactating women; 10. having used favipiravir or participated in any other interventional drug clinical study within 30 days prior to first dose of study drug. note: considering that covid-19 requires immediate treatment, absence of severe hepatic/renal disorders (e.g., cirrhosis, long-term dialysis) in the medical record can be used as an evidence for eligibility determination. it is recommended that hepatic function and creatinine be examined whenever possible.