Nitazoxanide (NTZ; NT-300; NT-675; PH 5776; nitazoxanide controlled-release tablets; nitazoxanide CR 675mg tablets; Tizoxanide; Alinia; Colufase; Cryptaz; Daxon; Heliton) is a first-in-class, small-molecule 5-nitrothiazole compound with antiparasitic, antibacterial and antiviral activity. Its exact mechanism of action has not yet been determined but studies suggest its activity in influenza is linked to inhibition of haemagglutinin. The antiviral mechanism also appears to involve the activation of protein kinase R, activated by double stranded ribonucleic acid, and leading to the phosphorylation of its substrate, eukaryotic initiation factor 2 alpha. Like interferons, thiazolides modulate cell signalling pathways involved in the host cell’s innate defence against viruses. Nitazoxanide is intended for the treatment of acute uncomplicated influenza infection. In clinical trials, nitazoxanide was administered orally at 300mg-600mg, twice daily for 5 days.
If licensed, nitazoxanide may provide an additional treatment option for uncomplicated influenza. It may be effective against influenza viruses resistant to neuraminidase inhibitors, exhibits activity against other respiratory viruses, and has not yet been associated with resistance.