Nitazoxanide

Nitazoxanide reduces parasite growth in cell culture by more than 90% with little evidence of drug-associated cytotoxicity. ^[1] Nitazoxanide is a new thiazolide antiparasitic agent that shows excellent in vitro activity against a wide variety of protozoa and helminths. ^[2] Nitazoxanide and its metabolite tizoxanide are more active in vitro than metronidazole against G. intestinalis, E. histolytica and T. vaginalis. ^[3] Nitazoxanide exhibits potent inhibition of both HBV and HCV replication. Nitazoxanide potentiates the effect of subsequent treatment with Nitazoxanide plus IFN, but not Nitazoxanide plus 2'CmeC, in HCV replicon-containing cells. Nitazoxanide induces reductions in several HBV proteins (HBsAg, HBeAg, HBcAg) produced by 2.2.15 cells, but does not affect HBV RNA transcription. ^[4] Nitazoxanide exhibits IC50, and IC90 values of 0.017 and 0.776 mg/mL respectively, against E. histolytica, 0.004 and 0.067 mg/mL against G. intestinalis, and 0.034 and 2.046 mg/mL against T. vaginalis. Nitazoxanide is more toxic than metronidazole and albendazole against E. histolytica. ^[5]

Nitazoxanide is partially effective at reducing the parasite burden in a gnotobiotic piglet diarrhea model when given orally for 11 days at 250 mg/kg/day but not at 125 mg/kg/day. Nitazoxanide induces a drug-related diarrhea in piglets that might have influenced its therapeutic efficacy. ^[1]