Early use of nitazoxanide in mild COVID-19 disease: randomised, placebo-controlled trial

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Abstract

Nitazoxanide is widely available and exerts broad-spectrum antiviral activity in vitro . However, there is no evidence of its impact on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Methods

In a multicentre, randomised, double-blind, placebo-controlled trial, adult patients presenting up to 3 days after onset of coronavirus disease 2019 (COVID-19) symptoms (dry cough, fever and/or fatigue) were enrolled. After confirmation of SARS-CoV-2 infection using reverse transcriptase PCR on a nasopharyngeal swab, patients were randomised 1:1 to receive either nitazoxanide (500 mg) or placebo, three times daily, for 5 days. The primary outcome was complete resolution of symptoms. Secondary outcomes were viral load, laboratory tests, serum biomarkers of inflammation and hospitalisation rate. Adverse events were also assessed.

Results

From June 8 to August 20, 2020, 1575 patients were screened. Of these, 392 (198 placebo, 194 nitazoxanide) were analysed. Median (interquartile range) 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. 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 reduced after nitazoxanide compared to placebo (p=0.006). The percentage viral load reduction from onset to end of therapy was higher with nitazoxanide (55%) than placebo (45%) (p=0.013). Other secondary outcomes were not significantly different. No serious adverse events were observed.

Conclusions

In patients with mild COVID-19, symptom resolution did not differ between nitazoxanide and placebo groups after 5 days of therapy. However, early nitazoxanide therapy was safe and reduced viral load significantly.

Article activity feed

  1. Andrew Hill

    Review 1: "Early use of nitazoxanide in mild Covid-19 disease: randomized, placebo-controlled trial"

    This paper presents potentially informative findings of the applicability of nitazoxanide in reducing viral load in patients with mild COVID-19. However, the reviewer raised concerns regarding the methods of analysis used in the study which may have had misleading implications

  2. SciScore for 10.1101/2020.10.21.20217208: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board StatementIRB: The trial was designed by the executive committee and approved by the Brazilian National Commission for Research Ethics and individual ethics committees of the participating sites (CAAE: 32258920.0.1001.5257).
    Consent: Informed consent was obtained from each patient or, if the patient was unable to provide consent, from a healthcare proxy.
    RandomizationRandomization and masking: Patients were randomly assigned (1:1) using a computer-generated random number list to receive either placebo or nitazoxanide (500 mg oral solution, 20 mg/mL [25 mL], three times daily for 5 days), dispensed by the pharmacy of each study site.
    Blindingnot detected.
    Power AnalysisStatistical Analyses: We estimated a sample size of 392 patients (196 per arm, allocation ratio 1:1) would provide 85% power to detect an 11% increase in symptom-free days after nitazoxanide initiation compared to placebo at a two-sided significance level of α=0.05.
    Sex as a biological variablenot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Statistical analyses were performed in the SPSS Version 27 environment
    SPSS
    suggested: (SPSS, RRID:SCR_002865)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).


    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    This study has several limitations. A long-term analysis of the effects of therapy (e.g., beyond 28 days) was not performed. Only three symptoms (dry cough, fever, and fatigue) were considered for analysis of primary outcome, even though Covid-19 is now known to have protean manifestations and patients reported other symptoms. Initially, patients were followed during the 5-day course of therapy; only those who continued to have one of the symptoms of interest after completion of therapy were contacted again 1 week later. At this second time point, nitazoxanide therapy was found to have reduced symptom duration significantly as compared to placebo. All patients were instructed to take their study medication 3 times daily as prescribed, return to the study site if symptoms worsened or adverse effects developed, and complete their symptom journals with data on any adverse events, the intensity of each Covid-19 symptom, and when symptoms abated and resolved. However, we cannot ascertain the extent to which patients followed these instructions. Nevertheless, given the placebo-controlled design, nonadherence may have occurred in both groups. In summary, in patients with mild Covid-19 enrolled within 3 days of symptom onset, nitazoxanide as compared with placebo was not an effective therapy in terms of accelerating symptom resolution after 5 days of therapy. However, at the 1-week follow-up, 78% in the nitazoxanide arm and 57% in the placebo arm reported complete resolution of sympt...

    Results from TrialIdentifier: We found the following clinical trial numbers in your paper:

    IdentifierStatusTitle
    NCT04552483CompletedEffects of Early Use of Nitazoxanide in Patients With COVID-…


    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.


    Results from JetFighter: We did not find any issues relating to colormaps.


    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a protocol registration statement.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  3. SciScore for 10.1101/2020.10.21.20217208: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board StatementThe trial was designed by the executive committee and approved by the Brazilian National Commission for Research Ethics and individual ethics committees of the participating sites (CAAE: 32258920.0.1001.5257).RandomizationAfter 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.Blindingnot detected.Power AnalysisStatistical Analyses We estimated a sample size of 392 patients (196 per arm, allocation ratio 1:1) would provide 85% power to detect an 11% increase in symptom-free days after nitazoxanide initiation compared to placebo at a two-sided significance level of α=0.05.Sex as a biological variableJust over half (53%) were women and 69% were white.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Statistical analyses were performed in the SPSS Version 27 environment
    SPSS
    suggested: (SPSS, RRID:SCR_002865)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).


    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:

    This study has several limitations. A long-term analysis of the effects of therapy (e.g., beyond 28 days) was not performed. Only three symptoms (dry cough, fever, and fatigue) were considered for analysis of primary outcome, even though Covid-19 is now known to have protean manifestations and patients reported other symptoms. Initially, patients were followed during the 5-day course of therapy; only those who continued to have one of the symptoms of interest after completion of therapy were contacted again 1 week later. At this second time point, nitazoxanide therapy was found to have reduced symptom duration significantly as compared to placebo. All patients were instructed to take their study medication 3 times daily as prescribed, return to the study site if symptoms worsened or adverse effects developed, and complete their symptom journals with data on any adverse events, the intensity of each Covid-19 symptom, and when symptoms abated and resolved. However, we cannot ascertain the extent to which patients followed these instructions. Nevertheless, given the placebo-controlled design, nonadherence may have occurred in both groups. In summary, in patients with mild Covid-19 enrolled within 3 days of symptom onset, nitazoxanide as compared with placebo was not an effective therapy in terms of accelerating symptom resolution after 5 days of therapy. However, at the 1-week follow-up, 78% in the nitazoxanide arm and 57% in the placebo arm reported complete resolution of sympt...


    Results from TrialIdentifier: We found the following clinical trial numbers in your paper:

    IdentifierStatusTitle
    NCT04552483CompletedEffects of Early Use of Nitazoxanide in Patients With COVID-...


    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.


    Results from JetFighter: We did not find any issues relating to colormaps.


    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.