Efficacy and safety of nitazoxanide in treating SARS-CoV-2 infection: a systematic review and meta-analysis of blinded, placebo-controlled, randomized clinical trials

Abstract

PurposeNitazoxanide is a broad-spectrum antiparasitic that has been tested for COVID-19 due to its anti-inflammatory effects and in vitro antiviral activity. This study synthesized the best evidence on the efficacy and safety of nitazoxanide in COVID-19.MethodsSearches for studies were performed in peer-reviewed and grey-literature from January 1, 2020 to May 23, 2022. The following elements were used to define eligibility criteria: (1) Population: individuals with COVID-19; (2) Intervention: nitazoxanide; (3) Comparison: placebo; (4) Outcomes: primary outcome was death, and secondary outcomes were viral load, positive RT-PCR status, serum biomarkers of inflammation, composite measure of disease progression (ICU admission or invasive mechanical ventilation), and any adverse events; (5) Study type: blinded, placebo-controlled, randomized clinical trials (RCTs). Treatment effects were reported as relative risk (RR) for dichotomous variables and standardized mean difference (SMD) for continuous variables with 95% confidence intervals (CI).ResultsFive blinded, placebo-controlled RCTs were included and enrolled individuals with mild or moderate SARS-CoV-2 infection. We found no difference between nitazoxanide and placebo in reducing viral load (SMD = − 0.16; 95% CI − 0.38 to 0.05) and the frequency of positive RTP-PCR results (RR = 0.92; 95% CI 0.81 to 1.06). In addition, there was no decreased risk for disease progression (RR = 0.63; 95% CI 0.38 to 1.04) and death (RR = 0.81; 95% CI 0.36 to 1.78) among patients receiving nitazoxanide. Patients with COVID-19 treated with nitazoxanide had decreased levels of white blood cells (SMD = − 0.15; 95% − 0.29 to − 0.02), lactate dehydrogenase (LDH) (SMD − 0.32; 95% − 0.52 to − 0.13), and D-dimer (SMD − 0.49; 95% CI − 0.68 to − 0.31) compared to placebo, but the magnitude of effect was considered small to moderate.ConclusionThis systematic review showed no evidence of clinical benefits of the use of nitazoxanide to treat patients with mild or moderate COVID-19. In addition, we found a reduction in WBC, LDH, and D-dimer levels among nitazoxanide-treated patients, but the effect size was considered small to moderate.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00228-022-03380-5.