Inclusion Criteria:

- Positive laboratory test for COVID-19 based on local laboratory standard

- Age greater than or equal to 18 years of age

- One of the following: Upper respiratory symptoms (cough, rhinorrhea) or fever (>101.5)
or loss of taste / smell

Exclusion Criteria:

- Randomization > 72 hours of meeting inclusion criteria

- Randomization > 7 days of symptom onset

- 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 women

- Females able to have children 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, condom use or abstinence during the study. All participants of
child bearing potential enrolled in this fashion will be informed of the teratogenic
risks.

- 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 (must be have
been measured within 1 month of enrollment)

4. Other kidney disease that in the opinion of the investigator, would affect
losartan clearance

- Patient reported dehydration and significantly decreased urine output in the past 72
hours

- Most recent systolic blood pressure prior to enrollment <110 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. Other liver disease that in the opinion of the investigator, would affect
losartan clearance

4. Documented AST or ALT > 3 times the upper limit of normal within 3 months of
randomization (if available in electronic medical record)

- Potassium >5.0 mmol/L (must have been measured within 1 month) of enrollment

- Concurrent treatment with aliskiren

- Inability to obtain informed consent

- Enrollment in another blinded randomized clinical trial for COVID