Study of Nitazoxanide in Adults With Acute Uncomplicated Influenza

• Time to resolution of all clinical symptoms of influenza (subjects infected with any respiratory virus) [ Time Frame: Up to 28 days ] [ Designated as safety issue: No ]
• Time to resolution of all clinical symptoms of influenza (all treated subjects) [ Time Frame: Up to 28 days ] [ Designated as safety issue: No ]
• Time to return to normal daily activity (subjects with confirmed influenza, subjects any respiratory virus and all treated subjects) [ Time Frame: Up to 28 days ] [ Designated as safety issue: No ]
• Severity of disease expressed in score-hours (symptom scores multiplied by duration of symptoms for subjects with confirmed influenza, subjects any respiratory virus and all treated subjects) [ Time Frame: Up to 28 days ] [ Designated as safety issue: No ]
• Time lost from work (subjects with confirmed influenza, subjects any respiratory virus and all treated subjects) [ Time Frame: Up to 28 days ] [ Designated as safety issue: No ]
• Complications of influenza including secondary illnesses, antibiotic use and hospitalizations (subjects with confirmed influenza, subjects any respiratory virus and all treated subjects) [ Time Frame: Up to 28 days ] [ Designated as safety issue: No ]
• Time to cessation of viral shedding (subjects with confirmed influenza) [ Time Frame: 7 days ] [ Designated as safety issue: No ]
• Change in influenza virus titer assessed by quantitative RT-PCR (subjects with confirmed influenza) [ Time Frame: 7 days ] [ Designated as safety issue: No ]

This is a randomized clinical trial designed to evaluate oral nitazoxanide compared to a placebo in the treatment of acute uncomplicated influenza in adults. We hypothesize that treatment with nitazoxanide will reduce the duration of symptoms in patients with confirmed influenza infection. Secondarily, we hypothesize that treatment with nitazoxanide will reduce the complications of influenza, severity of symptoms, time lost from work, time to return to normal daily activities, and viral shedding.

The study is conducted at approximately 25 sites in the United States. Subjects selected based on symptoms will be randomized to receive oral nitazoxanide or placebo twice daily for 5 days. Subjects will be monitored by daily by telephone or home visit to monitor symptoms and complications of influenza for safety and will be referred for medical care as required. Subjects will complete a diary twice daily to record the presence and severity of symptoms, ability to perform normal daily activities and time lost from work. Complications of influenza (including sinusitis, otitis, bronchitis, pneumonia, central nervous system disease) and other adverse events will be reported. Nasopharyngeal swabs will be collected at Baseline (Day 0) and Day 7 for all patients and on Days 1 through 4 for a subset of patients to test for influenza A (including novel H1N1), influenza B and 17 other respiratory viruses by RT-PCR and culture and to evaluate quantitative viral shedding. The primary analysis will be for patients with confirmed influenza, and secondary analyses will be conducted for subjects with any respiratory virus and for all treated subjects.

• Drug: Nitazoxanide
  Tablets, 500 mg with food twice daily for 5 days
  Other Name: Alinia, NTZ
• Drug: Placebo
  Tablet, twice daily with food for 5 days
  Other Name: Sugar pill

• Active Comparator: Nitazoxanide
  Intervention: Drug: Nitazoxanide
• Placebo Comparator: Placebo
  Intervention: Drug: Placebo

Inclusion Criteria:

• Age 18 to 65 years
• Fever, respiratory symptoms and constitutional symptoms compatible with influenza infection
• Influenza A or B infection in the local community
• Onset of illness no more than 48 hours before presentation
• Willing and able to provide comply with protocol requirements

Exclusion Criteria:

• Severity of illness requiring or anticipated to require in-hospital care
• High risk of complications from influenza per IDSA guidelines or current CDC criteria
• Females pregnant, breast-feeding or sexually active without birth control
• Vaccination for seasonal influenza or H1N1 on or after August 1, 2009
• Treatment with antiviral medication for influenza within 1 month prior to screening
• Treatment with nitazoxanide or any investigational drug within 1 month prior to screening
• Known sensitivity to nitazoxanide or any excipients
• Unable to take oral medications
• Chronic kidney or liver disease or known impaired hepatic and/or renal function
• Other pre-existing chronic infection undergoing or requiring medical therapy
• Pre-existing illness placing subject at unreasonably increased risk by participation in study
• Unlikely to comply with the requirements of this protocol