According to the New Drugs Online database, nitazoxanide inhibits haemagglutinin and modulates host cell signalling pathways involved in defence against viruses. It is currently under Phase II development in the US for influenza, and is also under investigation for the treatment of hepatitis C.
The authors of a Comment article discussing the results of this early-stage research note that the results suggest an effect size comparable to that achieved with the neuraminidase inhibitors. They go on to note that the ideal outcomes for such an agent would be a reduction in complications and mortality in the more vulnerable patients and those presenting with severe influenza. The results presented do not allow any determination of whether nitazoxanide can achieve this, as these patient groups were excluded from this study. Although trials of nitazoxanide in high-risk individuals are planned, it will be some time before their results are available, and therefore before the full public health relevance of this drug is known.