Early use of nitazoxanide in mild Covid-19 disease: randomized, placebo-controlled trial

The antiparasitic drug nitazoxanide is widely available and exerts broad-spectrum antiviral activity in vitro. However, there is no evidence of its impact on SARS-CoV-2 infection. In a multicenter, randomized, double-blind, placebo-controlled trial, adult patients who presented up to 3 days after onset of Covid-19 symptoms (dry cough, fever, and/or fatigue) were enrolled. After confirmation of SARS-CoV2 infection by RT-PCR on nasopharyngeal swab, patients were randomized 1:1 to receive either nitazoxanide (500 mg) or placebo, TID, for 5 days. The primary outcome was complete resolution of symptoms. Secondary outcomes were viral load, general laboratory tests, serum biomarkers of inflammation, and hospitalization rate. Adverse events were also assessed. From June 8 to August 20, 2020, 1,575 patients were screened. Of these, 392 (198 placebo, 194 nitazoxanide) were analyzed. Median time from symptom onset to first dose of study drug was 5 (4-5) days. At the 5-day study visit, symptom resolution did not differ between the nitazoxanide and placebo arms. However, at the 1-week follow-up, 78% in the nitazoxanide arm and 57% in the placebo arm reported complete resolution of symptoms (p=0.048). Swabs collected were negative for SARS-CoV-2 in 29.9% of patients in the nitazoxanide arm versus 18.2% in the placebo arm (p=0.009). Viral load was also reduced after nitazoxanide compared to placebo (p=0.006). No serious adverse events were observed. In patients with mild Covid-19, symptom resolution did not differ between the nitazoxanide and placebo groups after 5 days of therapy. However, early nitazoxanide therapy was safe and reduced viral load significantly.