Biochem/Physiol Actions | Nitazoxanide is a synthetic benzamide with antiprotozoal activity. Nitazoxanide exerts its antiprotozoal activity by interfering with the pyruvate ferredoxin/flavodoxin oxidoreductase dependent electron transfer reaction, which is essential to anaerobic energy metabolism. PFOR enzyme reduces nitazoxanide, thereby impairing the energy metabolism. However, interference with the PFOR enzyme-dependent electron transfer reaction may not be the only pathway by which nitazoxanide exhibits antiprotozoal activity. Nitazoxanide is active against Giardia lamblia and Cryptosporidium parvum. The active metabolite of this drug is tizoxanide (desacetyl-nitazoxanide). The initial reaction in the metabolic pathway of Nitazoxanide is hydrolysis to tizoxanide, followed by conjugation, primarily by glucuronidation to tizoxanide glucuronide. The oral suspension bioavailability of this drug is not equivalent to that of the oral tablets. Compared to the to the tablet, the bioavailability of the suspension was 70% [FDA label]. When administered with food, the AUCt of tizoxanide and tizoxanide glucuronide in plasma is increased to almost two-fold and the maximum concentration is increased by almost 50% compared to when ingested without food [FDA label]. When the oral suspension was ingested with food, the AUC of tizoxanide and tizoxanide glucuronide increased by approximately 50% and the Cmax increased by less than 10%. |
