Intervention: Nitazoxanide
Trial phase: Phase 2
ATC code: P01AX11
SMILES: CC(=O)Oc1ccccc1C(=O)Nc1ncc([N+](=O)[O-])s1
Sex: All
Age groups: Child | Adult | Older Adult
Healthy volunteers: No
Participants at risk: 130
Group description: Participants will receive NTZ for 5 days. Participants younger than 12 years will receive an oral suspension formulation of NTZ; participants 12 years and older will receive NTZ tablets.

Nitazoxanide (NTZ): Participants 1 to 3 years old: 5 mL oral suspension (100 mg NTZ) every 12 hours for 5 days.

Participants 4 to 11 years old: 10 mL oral suspension (200 mg NTZ) every 12 hours for 5 days.

Participants 12 years and older: two 300-mg NTZ tablets orally twice daily for 5 days.
Eligibility criteria:
Inclusion Criteria:

Signed informed consent prior to performance or initiation of any study procedures
Age greater than or equal to 12 months of age (no upper age limit)

Influenza-like illness (ILI), defined as (all of the following):

Onset of fever greater than or equal to 38°C (or hypothermia less than 36°C)
New or worse cough or sore throat
New or worse shortness of breath or difficulty breathing
Onset of illness no more than 5 days before screening defined as when the participant experienced at least 1 respiratory symptom, constitutional symptom, or fever
Hospitalization for ILI (decision for hospitalization will be up to the individual treating clinician), with anticipated hospitalization for more than 24 hours

One of the following to avoid pregnancy:

Females who are able to become pregnant (i.e., are not postmenopausal, have not undergone surgical sterilization, and are sexually active with men) must agree to use at least 1 effective form of contraception from the date of informed consent through Day 28 of study
Males who have not undergone surgical sterilization and are sexually active with women must agree to use condoms or have a partner use at least 1 effective form of contraception through Day 28 of study

Exclusion Criteria:

Women who are pregnant or breastfeeding
Clinical suspicion that etiology of illness is primarily bacterial in origin
Prior treatment with antivirals (e.g., oseltamivir) for the current illness for more than 24 hours
Unable to take oral medications (adults must tolerate tablets, children must tolerate suspension)
Unable to tolerate oral food/fluids (absorption is significantly better with food)
Prior treatment with any investigational drug therapy within 30 days prior to screening
Known sensitivity to NTZ or any of the excipients comprising the NTZ tablets
Prior NTZ use within 1 week
Self-reported history of chronic kidney disease or impaired renal function (no blood or urine kidney function laboratory testing will be done prior to enrollment, but intent is to exclude disease severe enough to cause estimated creatinine clearance [CrCl] less than 30)
Self-reported history of liver disease (no blood laboratory testing will be done prior to enrollment, but intent is to exclude disease severe enough to cause cirrhosis or total bilirubin greater than 2, aspartate aminotransferase [AST]/alanine aminotransferase [ALT] greater than 3 times the upper limit of normal [ULN])
Presence of any pre-existing illness that, in the opinion of the investigator, would place the participant at an unreasonably increased risk through participation in this study
Participants who, in the judgment of the investigator, will be unlikely to comply with the requirements of this protocol
The onset of SARI occurs after hospitalization
Hospitalized for any reason for greater than 48 hours prior to enrollment
Participants previously enrolled in this study
Prior hospital discharge within 30 days
Known chronic respiratory infection (e.g., tuberculosis, atypical mycobacterial infections)