Efficacy and Safety of Nitazoxanide for Post Exposure Prophylaxis of COVID-19 in Household Contacts

Pilot Study of Safety and Efficacy of Nitazoxanide in Post-exposure Prophylaxis in Household Contacts of Patients With Confirmed SARS-CoV-2 Infection

The primary objective of this study is to evaluate the efficacy of the drug nitazoxanide 500 mg, administered three times a day, in relation to placebo in preventing the development of COVID-19 in household contacts of patients diagnosed with the disease.

Eligible participants (cohabitants of a recently confirmed COVID19 case) residing in Buenos Aires City will be identified by the Ministry of Health and contacted with the investigators, who will visit them at home and offer to participate. For consenting individuals, a rapid serological test and a nasopharyngeal PCR sample for SARS-CoV-2 will be performed and participants will be then randomized to NTZ or placebo to be taken during 7 days.

SARS-CoV-2 PCR will be repeated on day 14th and the serologic rapid test repeated on day 28th.

Clinical status of participants will be assessed daily by phone. Individuals meeting case definition will be evaluated at home and a PCR will be performed. Those with confirmed COVID19 case will discontinue study medication and followed until symptoms resolution.

Inclusion Criteria:

• Men and women over 18 and under 65.
• Household contact with a confirmed case of COVID-19 by PCR for Sars-CoV-2.
• Initiate study medication within 4 days from the last close contact with the index case.
• The patient must not present symptoms suggestive of Covid19 (cough, dyspnea, fever> 37.5 C, fatigue, sore throat, myalgia, diarrhoea) at the time of admission to the study and from previous 14 days.
• Informed consent from the patient or legal representative.

Exclusion Criteria:

• History of infection confirmed by SARS-CoV-2.
• Positive IgG antibodies test for SARS-CoV-2 at the time of admission.
• Have received any dose of nitazoxanide within 7 days prior to screening.
• Known hypersensitivity to any of the study medication components.
• Use of any investigational or unregistered drug or vaccine within 30 days prior to screening, or use planned during the study period.
• Inability to comply with study procedures.
• Current breastfeeding.
• Pregnancy.
• Intolerance or inability to take oral medication.
• History of severe liver disease (Child-Pugh B or C) and/or chronic kidney disease.