Efficacy and Safety of Nitazoxanide 600 mg to Treat Mild Ambulatory COVID-19 Patients

Inclusion Criteria: * Informed consent from patient or legal representative. * Subject of both genders (male and female not pregnant and not breastfeeding) aged over 49; * Laboratory confirmation of 2019-nCoV infection by reverse-transcription polymerase chain reaction (RT-PCR) from any diagnostic sampling source; * Symptomatic subject with symptoms for up to 72 hours who does not require hospitalization, with signs and symptoms of acute respiratory viral infection characterized by a feverish sensation or fever, which may or may not be present at the time of the examination (which may be reported to the health professional), accompanied by cough or sore throat or runny nose or difficulty breathing and: i) Oxygen saturation ≥ 90%; ii) Risk classification for COVID-19 between low (A) or medium (B) (scores 1 to 19), according to the Brazilian Ministry of Health. Exclusion Criteria: * Participating in another RCT in the past 12 months; * Presence of comorbidities, which have a contraindication to the use of the study product, not being restricted to: * HIV or HTLV virus infection; * Chronic hepatitis C (HCV) treated with direct antiviral drugs; * Liver failure; * Severe renal failure, including dialysis; * Present hypersensitivity to the study product (nitazoxanide), as well as to related compounds; * Concomitant administration of drugs that may interact with the product under study (nitazoxanide); * Participants who underwent treatment with other antiviral drugs; * Subject in antineoplastic treatment with chemotherapy or radiation therapy; * Subject with severe autoimmune diseases in immunosuppression; * Transplanted participants; * Pregnant or lactating women; * Any other clinical condition that is deemed by the Investigator to be an imminent risk to the health and life of the subject.