Effects of Nitazoxanide Administration to Patients in the Initial Phase of COVID-19

INTERVENTION: /drug effects Drug Off‐Label Use Patients diagnosed with COVID‐19 will be randomly divided into 2 groups: experimental and control groups. Experimental group: 196 patients diagnosed with COVID‐19 confirmed by RT‐PCR will receive nitazoxanide 500mg 8/8 hs for 5 days. Control group: 196 patients diagnosed with COVID‐19 confirmed by RT‐PCR will receiveplacebo 8/8 hs for 5 days. CONDITION: Coronavirus infection, unspecified / COVID‐19 ; Coronavirus infection, unspecified A00‐B99 Coronavirus infection, unspecified PRIMARY OUTCOME: Reduction in the duration of cough of patients with COVID‐19 submitted to the therapeutic protocol with nitazoxanide compared to patients treated with placebo; verified through the collection of information with the patient; quantified by the number of days that presented the symptom.; Reduction in the duration of fatigue of patients with COVID‐19 submitted to the therapeutic protocol with nitazoxanide compared to patients treated with placebo; verified through the collection of information with the patient; quantified by the number of days that presented the symptom.; Reduction in the duration of fever of patients with COVID‐19 submitted to the therapeutic protocol with nitazoxanide compared to patients treated with placebo; verified through the collection of information with the patient; quantified by the number of days that presented the symptom.; INCLUSION CRITERIA: Will be included in the study of patients of both genders who meet all of the following requirements: clinical scenario compatible with infection by the SARS‐CoV‐2 [Characteristic symptoms of COVID‐19 (fever and / or drought and / or fatigue), beginning 1 to 3 days before inclusion in the study; age equal or superior to 18 years; willingness to receive study treatment; providing written and informed consent or the same consent signed by a family member. SECONDARY OUTCOME: Assess the incidence and profile of adverse events reported throughout the study, by treatment group; verified by information actively collected from patients or family members; quantified by absolute number and percentage. Assess the rate of treatment discontinuation due to adverse events; verified by information actively collected from patients or family members; quantified by absolute number and percentage. Compare the evolution of viral load in naso‐ and oropharyngeal swab in patients with COVID‐19 treated with nitazoxanide or placebo on days 1 and 8; verified using the RT‐PCR technique; quantified by the absolute and percentage change between the two days Compare the hospital admission rate of patients with COVID‐19 submitted to the therapeutic protocol with nitazoxanide with patients with COVID‐19 treated with placebo, in the period of 8 days; verified by information actively collected from patients or family members; quantified by absolute number and percentage. Compare the levels of inflammatory mediators: (interleukin [IL] ‐6, IL‐1‐beta, IL‐8, interferon gamma, tumor necrosis factor [TNF] ‐alpha, monocyte chemoattract protein [MCP] ‐1) from patients with COVID‐19 submitted to the therapeutic protocol with nitazoxanide with patients with COVID‐19 treated with placebo, on days 3 and 8; verified by the measurement of cytokines in patient serum by the ELISA technique; quantified by the absolute number and percentage between the two days. Evaluate evolution of complete blood count, total and differential leukogram of patients with COVID‐19 submitted to the therapeutic protocol with nitazoxanide with patients with COVID‐19 treated with placebo, on days 3 and 8; verified by laboratory tests and expressed by the absolute number and percentage between the two days. To evaluate the levels of C‐reactive protein (CRP) of patients with COVID‐19 submitted to the therapeutic protocol with nitazoxanide with patients with COVID‐19 treated with placebo, on days 3 and 8; verified by laboratory tests and expressed by the absolute number and percentage between the two days.