Losartan for Patients With COVID-19 Requiring Hospitalization

Inclusion Criteria: * Presumptive positive laboratory test for Covid-19 based on local laboratory standard * Age greater than or equal to 18 years of age * Admission to the hospital with a respiratory SOFA \>=1 and increased oxygen requirement compared to baseline among those on home O2 * Randomization within 48 hours of presentation of hospital admission or within 48 hours of a positive test result, whichever is later Exclusion Criteria: * Randomization \> 48 hours of admission order or positive test result, whichever is later * Currently taking an angiotensin converting enzyme inhibitor (ACEi) or Angiotensin receptor blocker (ARB) * Prior reaction or intolerance to an ARB or ACE inhibitor, including but not limited to angioedema * Pregnant or breastfeeding * Lack of negative urine or serum pregnancy test * Not currently taking a protocol allowed version of contraception: intrauterine device, Depo-formulation of hormonal contraception (e.g. medroxyprogesterone acetate / Depo-Provera), subcutaneous contraceptive (e.g. Nexplanon), daily oral contraceptives with verbalized commitment to taking daily throughout the study period; use of condoms or agree to abstain from sexual intercourse during the study. All women of child bearing age enrolled in this fashion will be informed of the teratogenic risks. If enrolled under LAR, they will be informed of the risks after regaining capacity. * Patient reported history or electronic medical record history of kidney disease, defined as: 1. Any history of dialysis 2. History of chronic kidney disease stage IV 3. Estimated Glomerular Filtration Rate (eGFR) of \< 30ml/min/1.73 m2 at the time of randomization * Severe dehydration at the time of enrollment in the opinion of the investigator or bedside clinician * Most recent mean arterial blood pressure prior to enrollment \<65 mmHg * Patient reported history or electronic medical record history of severe liver disease, defined as: 1. Cirrhosis 2. History of hepatitis B or C 3. Documented AST or ALT \> 3 times the upper limit of normal measured within 24 hours prior to randomization * Potassium \>5.0 within 24 hours prior to randomization unless a repeat value was \<=5.0 * Treatment with aliskiren * Inability to obtain informed consent from participant or legally authorized representative * Enrollment in another blinded randomized clinical trial for COVID