 Nitazoxanide is an effective first-line treatment for infection by "Blastocystis" species and is indicated for the treatment of infection by "Cryptosporidium parvum" or "Giardia lamblia" in immunocompetent adults and children.It is also an effective treatment option for infections caused by other protozoa and helminths (e.g., "Entamoeba histolytica", "Hymenolepis nana", "Ascaris lumbricoides", and "Cyclospora cayetanensis")., it is in phase 3 clinical trials for the treatment influenza due to its inhibitory effect on a broad range of influenza virus subtypes and efficacy against influenza viruses that are resistant to neuraminidase inhibitors like oseltamivir.