Eligibility Criteria:
Inclusion Criteria:
* Subjects must be 45 years of age or older
* Provision of informed consent
* Subjects who tested positive for SARS-CoV-2 AND have clinical symptoms of COVID-19\* AND have been hospitalized, but are not requiring more than 4 liters/minute of supplemental oxygen by nasal cannula and are not requiring ICU/CCU-level care at time of enrollment
(\*)Acute respiratory tract infection (sudden onset of at least one of the following: fever, chills, sore throat, myalgia, diarrhea, cough, or shortness of breath) AND with no other etiology that fully explains the clinical presentation
Exclusion Criteria:
* Female subjects who identify as pregnant, self-reported positive pregnancy testing, or who are breastfeeding during the study period
* Age \>85 years
* Known history of known orthostatic hypotension, unexplained history of syncope, postural orthostatic tachycardia syndrome (POTS), neurally-mediated hypotension, heart failure, myocardial infarction, stable or unstable angina, history of coronary artery bypass surgery, stroke, carotid artery disease, or moderate to severe mitral or aortic stenosis
* Current use of tocilizumab, sarilumab, siltuximab, lopinavir/ritonavir, remdesivir, favipiravir, alpha-blockers, combined alpha/beta blockers (carvedilol, labetalol), sotalol, clonidine, phosphodiesterase type 5 inhibitors, asenapine, or alpha-methyldopa
* Need for vasopressors, inotropes, or intra-aortic balloon pump at time of enrollment
* Allergy or intolerance to quinazolines (including prazosin)
* Requires oxygen supplementation beyond 4 liters of oxygen/minute per nasal cannula at time of enrollment (i.e. not requiring oxygenation by non-rebreather, high-flow nasal cannula, CPAP/BiPAP, or invasive mechanical ventilation)
* Patients who are in the custody of state or federal entities (prisoners)