Nitazoxanide

Limits on what this shows

• Null findings: No human study measured mitochondrial function on nitazoxanide, and none was found reporting a mitochondrial adverse effect. The label adverse reaction list (abdominal pain, headache, chromaturia, nausea) contains no mitochondrial or myopathic event [1][2].
• At-risk subgroups: Not defined. Renal and hepatic impairment pharmacokinetics are unstudied [1].

Regulatory status

The label names PFOR interference as the mechanism and says nothing about mitochondria [1][2].

Population evidence

No human data. Tier B, drug-specific, preclinical: (1) Amireddy 2017 [4]: nitazoxanide reversed MPP+ blockade of respiration through mild uncoupling effects in cultured cells, and oral nitazoxanide 50 mg/kg protected dopaminergic neurons in an acute MPTP mouse model (reconstructed OpenAlex abstract). (2) Li 2022 [5]: nitazoxanide and tizoxanide induced mild mitochondrial uncoupling and activated AMPK in HepG2 cells, with lower liver lipid in high-fat-fed hamsters and mice (abstract-level summary). (3) Ma 2022 [6]: tizoxanide showed uncoupling and AMPK activation, measured by high-resolution respirometry; nitazoxanide reduced atherosclerosis in ApoE-deficient mice. (4) A 2022 preprint [7]: tizoxanide, a nitro-free thiazolide and CCCP produced matching antiviral effects when matched for uncoupling intensity; tizoxanide did not act on the ATP/ADP exchanger or the permeability transition pore.

Mechanism

Named: protonophore-like uncoupling. The preprint reports patient tizoxanide levels of 7.5 micromolar after a single dose (2 mg/L); the label Cmax of 10.6 ug/mL is about 40 micromolar total by my calculation (molecular weight about 265), though more than 99% is protein bound [1][7]. Whether the free concentration reaches uncoupling range in patients was not shown in any source opened.

Counter-evidence held on record

Counter-evidence Three of four papers frame the uncoupling as protective or therapeutic (neuroprotection, anti-steatosis, anti-atherosclerosis). A 2021 correction to Amireddy 2017 exists (Crossref listing only; its content was not read), so the original findings carry a caveat of unknown scope [4]. Framing caution Preclinical mechanism, not a patient finding. Do not present as mitochondrial damage or as an energy deficit, and do not suggest supplements from this entry.

Limits on what this shows

• Null findings: No human redox marker study located. The label lists no oxidative adverse reaction [1][2].
• At-risk subgroups: Not defined.

Regulatory status

Not addressed in the label extracts [1][2].

Population evidence

No human data. Lower: Amireddy 2017 [4]: pretreatment reduced MPP+-induced reactive oxygen species in cells. Rat methotrexate study 2024 [14]: in 36 rats given methotrexate, nitazoxanide at 100 and 200 mg/kg/day reduced malondialdehyde and enhanced antioxidant capacity, dose-dependently (specific values not retrieved). Higher: Gong 2021 [13]: nitazoxanide raised reactive oxygen species in zebrafish embryo hearts, with oxidative stress pathways up-regulated and a fullerene antioxidant reducing injury. Albogami 2024 [15]: in 32 male rats at 18 mg/kg daily for 30 days, nitazoxanide lowered SOD, catalase and GPx and raised MDA, with ellagic acid attenuating. Albogami 2026 [16]: in male mice for 30 days nitazoxanide alone caused renal dysfunction and oxidative damage, reversed by a zinc complex (abstract-level).

Mechanism

Not established. The protective and harmful results come from different models, doses and species, and no study tested them against each other in one system. The cited papers propose their own pathways (ER stress and apoptosis in [14], an oxidative stress response in [13]); none identifies a single mechanism for the drug.

Counter-evidence held on record

Counter-evidence The two harmful rodent studies [15][16] come from one author group using a similar 30-day design (18 mg/kg daily in the 2024 study; the 2026 dose was not retrieved). Their human relevance is unclear, and neither was a human or a patient-population study. The protective result [14] was obtained in a methotrexate toxicity model, where protection against another toxin is not evidence about baseline status. Framing caution Do not recommend antioxidant supplements. Redox balance is a research question here, not a deficiency.

Limits on what this shows

• Null findings: No iron, ferritin or hemoglobin measurement on nitazoxanide was found. The cohort test fails for both giardiasis studies [18][19]: nitazoxanide was not studied, so this is a context flag, not a class extrapolation.
• At-risk subgroups: Children and others with persistent giardiasis, menstruating women, and people with poor intake (context, not a drug finding).

Regulatory status

No iron, anemia or hemoglobin statement in the label extracts [1][2].

Population evidence

Context only, with nitazoxanide not in either cohort. Monajemzadeh 2008 [18]: 102 children aged 5 to 11 with giardiasis; iron deficiency anemia in about one-quarter; after metronidazole (15 mg/kg/day for 5 days), mean hemoglobin, hematocrit, ferritin and serum iron to TIBC ratio rose (P<0.0001); pre-post design, no control group. Fattahi bafghi 2025 [19]: case-control, 70 children (35 infected, 35 healthy); serum iron lower (P=0.03) and ferritin lower (59 vs 110, P=0.001) in infected children; no treatment arm.

Mechanism

Absent for the drug: no iron-binding, absorption or loss mechanism is described in the label or in any nitazoxanide source opened. The infection plausibly impairs absorption and increases loss; this is a disease mechanism.

Counter-evidence held on record

Counter-evidence and confounding Confounding by indication is the whole story here: the condition treated causes the iron signal, and treatment (a different drug) was followed by improvement. Anemia is not iron deficiency, and neither is a nitazoxanide effect on this evidence (Hard Rule 2). Framing caution Do not tell readers nitazoxanide lowers iron. Do not recommend iron supplements from this entry; excess iron has its own risks.

Limits on what this shows

• Null findings: No serum copper, ceruloplasmin or urinary copper study on nitazoxanide was found.
• At-risk subgroups: Not defined.

Regulatory status

No copper statement in the label extracts [1][2].

Population evidence

Tier B, in vitro chemistry: a 2023 Molecules paper [17] prepared nitazoxanide complexes with Cu(II), Ni(II) and Zn(II) at 2:1 ligand to metal, reporting a DNA binding constant of 7.00 x 10^5 per molar for the copper complex, with antioxidant, antibacterial and anticancer assays (abstract-level summary).

Mechanism

Coordination chemistry in preparative conditions. No physiological chelation, absorption or excretion of copper was measured.

Counter-evidence held on record

Counter-evidence The study aimed to improve the drug through metal coordination and says nothing about nutritional copper. Graded yellow because the Step 7 rule requires at least yellow once any Tier B source exists; it would carry no weight on its own. Framing caution Not a copper-depletion or copper-excess claim. Do not recommend copper or zinc supplements from this entry.

Limits on what this shows

• Null findings: Maier 2018 screened 1,197 drugs against gut isolates [21]; the retrieved text did not mention nitazoxanide, which is a tooling null (supplementary tables may not have been read) and supports no inference. No C. difficile recurrence or dysbiosis dataset for nitazoxanide was opened.
• At-risk subgroups: Not defined. Children with diarrheal illness already have disturbed flora regardless of drug, so baseline confounding is strong.

Regulatory status

The label microbiology section covers protozoa only; no statement on normal flora [1][2].

Population evidence

No in vivo composition data. Tier B, in vitro: Hoffman 2007 [9] showed nitazoxanide inhibiting PFOR of C. difficile, C. perfringens, H. pylori and C. jejuni, and noted it is not active against Lactobacillus and Propionibacterium, which lack PFOR. Halsey 2009 review [10] lists activity against C. difficile, Bacteroides and Prevotella species. Freeman 2011 [11] reported activity against C. difficile strains with reduced metronidazole susceptibility; the repository record held only the abstract, with no commensal data. Hossain 2025 [20]: pilot randomized trial in 64 Bangladeshi children with cryptosporidiosis (nitazoxanide plus L. reuteri, nitazoxanide plus placebo, or standard care); the retrieved text reported infection duration and growth only and no sequencing result.

Mechanism

Named: PFOR inhibition in susceptible anaerobes plus a large fecal share of the dose (about two-thirds) [1][9]. Sparing of PFOR-lacking taxa is a mechanism-based expectation from [9], not a measured microbiome result.

Counter-evidence held on record

Counter-evidence and confounding The infection itself (Giardia, Cryptosporidium, C. difficile) alters the microbiome, so any post-treatment change cannot be assigned to the drug without a comparator. In vitro susceptibility of a few taxa does not predict community-level change. Framing caution Theoretical only. This is not evidence for or against routine probiotics, and it is not a deficiency claim.

Limits on what this shows

• Null findings: In the mammalian cell work retrieved, ATP was preserved or restored at mild uncoupling [4][7]. No source reported ATP depletion in human cells at therapeutic exposure.
• At-risk subgroups: Not defined.

Regulatory status

Not addressed in the label extracts [1][2].

Population evidence

No human data. Tier B: Amireddy 2017 [4]: nitazoxanide ameliorated MPP+-induced loss of oxygen consumption and ATP production through mild uncoupling, reversible on drug removal. 2022 preprint [7]: mild uncoupling (25 to 50% interference with oxidative phosphorylation) preserved cellular ATP balance, while 75 to 100% interference changed viral RNA release; ATP, ATP/O ratio and adenylate energy charge were measured in mouse cells. Atherton 2004 thesis [8]: ATP synthesis was inhibited significantly by 33 micromolar nitazoxanide in C. elegans and S. mansoni, and oxygen uptake rose in H. diminuta mitochondria comparably to known protonophores.

Mechanism

Named: uncoupling raises oxygen consumption while limiting ATP yield per oxygen at higher intensity. The helminth inhibition [8] is part of the intended antiparasitic effect, not a human finding.

Counter-evidence held on record

Counter-evidence The thesis [8] is a doctoral thesis, not a peer-reviewed paper, and used parasite and nematode systems. The preprint [7] has not been confirmed as peer reviewed in anything retrieved. Its authors were not captured by the summarizer. Framing caution Do not translate any of this into "low energy" or fatigue. No source links nitazoxanide to reduced energy in people.

Limits on what this shows

• Null findings: No clinical report of anemia, hemolysis or methemoglobinemia on nitazoxanide was located. A search for G6PD-related case reports surfaced only reports for other agents.
• At-risk subgroups: Not defined from in vitro data.

Regulatory status

No hematologic, methemoglobin or hemolysis event appears in the label adverse reaction extracts [1][2]. The 2009 review reported no hematologic adverse events [10].

Population evidence

Tier B, in vitro: Arnold 2014 [12]: erythrocytes exposed for 48 hours to nitazoxanide 1 to 50 ug/mL. Cytosolic calcium did not change significantly; ceramide rose at 10 ug/mL and above; cell volume fell; annexin-V binding was reduced; hemolysis increased at 20 ug/mL and above (reconstructed OpenAlex abstract).

Mechanism

Named: calcium-independent ceramide formation causing eryptosis-like change. The label Cmax of tizoxanide is 10.6 ug/mL [1], near the lowest effective concentration, but the parent drug was tested and is not detected in plasma, tizoxanide is more than 99% protein bound, and the protein content of the assay medium was not read.

Counter-evidence held on record

Counter-evidence The reduced annexin-V binding runs opposite to the usual eryptosis marker, which the authors do not fully reconcile in the abstract. The study is a single cell assay from one laboratory. Framing caution Not an oxygen-delivery finding in patients. Anemia seen during giardiasis is a disease effect (see Iron and Fails verification), not evidence from this entry.