- age <18 years; age >80 years - pregnant or breast feeding woman or with positive pregnancy test result p/f <100 mmhg - moribund condition (death likely in days) or not expected to survive for >7 days refusal by attending md - not hemodynamically stable in the preceding 4 hours (map ≤65 mmhg, or sap <90 mmhg, dap <60 mmhg, vasoactive agents are required) - patient on invasive mechanical ventilation or ecmo - patient in other therapeutic clinical trial within 30 days before icf - receive any other ace inhibitors (acei), angiotensin-receptor blockers (arb) treatment within 7 days before icf - chronic immunosuppression: current autoimmune diseases or patients who received immunotherapy within 30 days before icf - hematologic malignancy (lymphoma, leukemia, multiple myeloma) - other patient characteristics (not thought to be related to underlying covid-19) that portend a very poor prognosis (e.g, severe liver failure, and ect) - known allergy to study drug or its ingredients related to renin-angiotensin system (ras), or frequent and/or severe allergic reactions with multiple medications - other uncontrolled diseases, as judged by investigators - body weight ≥85 kg

- age <18 years; age >80 years - pregnant or breast feeding woman or with positive pregnancy test result p/f <100 mmhg - moribund condition (death likely in days) or not expected to survive for >7 days refusal by attending md - not hemodynamically stable in the preceding 4 hours (map ≤65 mmhg, or sap <90 mmhg, dap <60 mmhg, vasoactive agents are required) - patient on invasive mechanical ventilation or ecmo - patient in other therapeutic clinical trial within 30 days before icf - receive any other ace inhibitors (acei), angiotensin-receptor blockers (arb) treatment within 7 days before icf - chronic immunosuppression: current autoimmune diseases or patients who received immunotherapy within 30 days before icf - hematologic malignancy (lymphoma, leukemia, multiple myeloma) - other patient characteristics (not thought to be related to underlying covid-19) that portend a very poor prognosis (e.g, severe liver failure, and ect) - known allergy to study drug or its ingredients related to renin-angiotensin system (ras), or frequent and/or severe allergic reactions with multiple medications - other uncontrolled diseases, as judged by investigators - body weight ≥85 kg