Nitazoxanide 500 mg · Tablets

Nitazoxanide is an antiprotozoal [see Microbiology ( 12.4)].

Single Dosing: — Following oral administration of nitazoxanide tablets, the parent drug, nitazoxanide, is not detected in plasma. The pharmacokinetic parameters of the metabolites, tizoxanide and tizoxanide glucuronide are shown in Tables 2 and 3 below.

Multiple dosing: — Following oral administration of a single nitazoxanide tablet every 12 hours for 7 consecutive days, there was no significant accumulation of nitazoxanide metabolites tizoxanide or tizoxanide glucuronide detected in plasma.

Bioavailability: — Alina for oral suspension is not bioequivalent to nitazoxanide tablets. The relative bioavailability of the suspension compared to the tablet was 70%.

When nitazoxanide tablets are administered with food, the AUC τof tizoxanide and tizoxanide glucuronide in plasma is increased almost two-fold and the C maxis increased by almost 50%.

Nitazoxanide tablets were administered with food in clinical trials and hence they are recommended to be administered with food [see Dosage and Administration ( 2.1)] .

Distribution — In plasma, more than 99% of tizoxanide is bound to proteins.

Metabolism — Following oral administration in humans, nitazoxanide is rapidly hydrolyzed to an active metabolite, tizoxanide (desacetyl-nitazoxanide). Tizoxanide then undergoes conjugation, primarily by glucuronidation.

Excretion — Tizoxanide is excreted in the urine, bile and feces, and tizoxanide glucuronide is excreted in urine and bile. Approximately two-thirds of the oral dose of nitazoxanide is excreted in the feces and one-third in the urine.

Pediatric Patients — The pharmacokinetics of tizoxanide and tizoxanide glucuronide following administration of nitazoxanide tablets in pediatric patients 12 to 17 years of age are provided above in Table 2. Mean (±SD) plasma pharmacokinetic parameters of tizoxanide and tizoxanide glcuronide following administration of a single dose of one 500 mg nitazoxanide tablet with food to subject ≥12 years of age.

Drug Interaction Studies — In vitrostudies demonstrated that tizoxanide has no significant inhibitory effect on cytochrome P450 enzymes.