Meloxicam

Limits on what this shows

• Null and reverse findings: A rat quinolinic acid Huntington-like model study (PubMed listing text only) reported that meloxicam 10 to 20 mg/kg restored mitochondrial enzyme complex activities [32], a reverse direction in a disease model. Nadanaciva's abstract does not single out meloxicam as toxic [19].

Regulatory status

No mitochondrial statement in the meloxicam label sections retrieved [1]. Label hepatotoxicity statement (ALT or AST at 3 times or more the upper limit in about 1% of NSAID-treated patients) is a class clinical outcome, not a mitochondrial finding.

Population evidence

None in humans. Moreno-Sanchez 1999 [18] (Tier B, in vitro; rat liver and heart mitochondria and hepatocytes per the retrieved record): the abstract text retrieved states that diclofenac, piroxicam, indomethacin, naproxen, nabumetone, nimesulide and meloxicam were tested for effects on mitochondrial respiration, ATP synthesis and membrane potential, and that plots of membrane potential against ATP synthesis or respiration showed proportional variations at different concentrations of nimesulide, meloxicam, piroxicam or indomethacin. One summarizing retrieval characterized meloxicam, nimesulide and piroxicam as behaving similarly as mitochondrial uncouplers. A separate summarizing retrieval described meloxicam as stimulating basal and uncoupled respiration, inhibiting ATP synthesis and collapsing membrane potential; that wording could not be matched to the abstract text and is not relied on. Concentrations were not available. Nadanaciva 2013 [19]: meloxicam was one of 11 NSAIDs tested on rat liver mitochondrial respiration, rat hepatocyte endpoints and zebrafish; the abstract reports good concordance across chemical classes and correct separation of toxic from non-toxic drugs, but gives no meloxicam-specific result (full text not opened).

Mechanism

Named and demonstrated in vitro: protonophore-like uncoupling by NSAIDs, with meloxicam among those studied [18]. Whether free plasma meloxicam concentrations in people reach uncoupling levels is not shown; the label reports about 99.4% plasma protein binding (primarily albumin) [1].

Counter-evidence held on record

Counter-evidence Isolated-mitochondria uncoupling is a screening-level finding; the same panel is described as predicting NSAID safety profiles, and no clinical mitochondrial toxicity signal for meloxicam appears in the label sections retrieved. Framing caution Mechanistic plausibility only. This entry does not support any mitochondrial or antioxidant supplement and is not a deficiency claim.

Limits on what this shows

• Null and reverse findings: No change in erythrocyte malondialdehyde in humans [20]. Several rodent and cell studies in disease models (inflammation, stress, toxin) report antioxidant or Nrf2-activating effects of meloxicam (PubMed listing text only, not opened). A dog study found no erythrocyte oxidative damage from meloxicam [31].

Regulatory status

No oxidative-stress statement in the label sections retrieved [1].

Population evidence

Cimen 2003 [20] (Tier A for the endpoint, but small and uncontrolled): osteoarthritis patients given meloxicam 15 mg/day (n=12), celecoxib 200 mg/day (n=12) or ibuprofen 1,200 mg/day (n=9) for 21 days; erythrocyte superoxide dismutase activity fell significantly from baseline in all groups, and malondialdehyde did not differ significantly pre versus post. There was no placebo arm. Khan and Rampal 2014 [21]: rabbits (n=4 per group, 21 days oral); reduced glutathione fell significantly with meloxicam alone, and lipid peroxidation rose significantly versus controls. Khan 2017 [22]: rabbits, meloxicam 0.2 mg/kg/day alone or with fluoroquinolones (n=4 per group); the abstract concludes enrofloxacin caused greater oxidative damage than meloxicam and does not give meloxicam-alone values. Karaman 2011 [24]: meloxicam inhibited purified human erythrocyte glutathione reductase non-competitively (IC50 0.029 mM, Ki 0.0061 mM). Pawlukianiec 2020 [23]: in an in vitro oxidized albumin model meloxicam showed radical scavenging, ferric-reducing and anti-glycation activity comparable to captopril, Trolox, glutathione, lipoic acid and aminoguanidine.

Mechanism

Both directions are chemically plausible: direct scavenging in vitro [23], enzyme inhibition [24] and reduced SOD activity [20]. Which dominates in vivo is unresolved.

Why not orange

Orange needs a bounded real deficit with the endpoint clearly attributable to the drug. [20] is a 12-person pre/post comparison with no control, disease activity changed over the same period, the oxidant damage marker did not move, and SOD activity is an enzyme level rather than a nutrient status.

Counter-evidence held on record

Counter-evidence Direction conflicts across species and models, doses in animals are not mapped to human exposure, and the human data cannot separate drug from resolving inflammation. Framing caution Do not describe meloxicam as depleting antioxidants and do not describe it as an antioxidant therapy. No antioxidant supplement is implied.

Limits on what this shows

• Null findings: Controlled fecal blood loss with meloxicam was not distinguishable from placebo in healthy men over 4 weeks [6], and the pooled review put meloxicam among the lower-loss NSAIDs [5]. Both are short-exposure studies in mostly young healthy volunteers, so they do not test older arthritis patients on years of therapy. Upper GI ulcers, gross bleeding or perforation occur in about 1% of NSAID-treated patients at 3 to 6 months and 2 to 4% at one year (label class statement) [2].
• At-risk subgroups: Older adults (label sec 8.5), people on anticoagulants or other drugs affecting hemostasis, aspirin co-users, people with prior GI bleeding, and longer or higher-dose exposure [1].

Regulatory status

Label sec 5.2 warns of GI bleeding, ulceration and perforation; sec 5.12 states anemia has occurred in NSAID-treated patients, that it may be due to occult or gross blood loss, fluid retention or an incompletely described effect on erythropoiesis, and advises hemoglobin or hematocrit monitoring if signs of anemia appear. Iron itself is not mentioned [1]. An older label version reports anemia in 4.1% (7.5 mg, n=169) and 2.9% (15 mg, n=306) of patients in 6-month active-controlled osteoarthritis trials; the retrieved table gave no comparator column [2].

Population evidence

Castellsague 2012 [7]: cohort with nested case-control, 588,827 NSAID users and 3,031 upper GI complications; meloxicam fell in the RR 2 to under 5 band versus non-use (the exact meloxicam RR was not in the abstract; the SOS meta-analysis abstract [8] also gave no meloxicam estimate). Outcome is GI complication, not iron status. Moore 2008 [5]: systematic review of 47 randomized trials (1,162 people, mostly healthy young men) using 51-chromium red-cell labeling; diclofenac, meloxicam and etodolac were grouped at about 0.5 to 0.9 mL/day of fecal blood loss against placebo 0.76 mL/day and untreated 0.46 mL/day (individual meloxicam arm data were not reported in the text read). Patoia 1996 [6]: 51 healthy men, 4 weeks, meloxicam 7.5 mg and 15 mg vs piroxicam 20 mg vs placebo; no significant difference in fecal blood loss across groups, while piroxicam exceeded placebo. Han 2025 [9]: 888,909 Korean osteoarthritis patients, five NSAID subtypes; anemia confirmed as a class adverse effect (no meloxicam-specific anemia estimate in the abstract). Case reports (Tier B): 77-year-old man with chronic iron-deficiency anemia and terminal ileal ulcers on chronic meloxicam, inflammatory markers normalized and ulcers resolved after stopping [10]; a 60-year-old woman with anemia, tarry stools and small-bowel ulcers after long-term meloxicam [11] (PubMed listing text only, abstract not opened).

Mechanism

Present. Meloxicam inhibits prostaglandin synthesis through COX-1 and COX-2 inhibition (label sec 12.1 [1]), and NSAID mucosal injury of the stomach and small bowel can bleed. The iron loss itself (ferritin, transferrin saturation, serum iron) was not measured in any retrieved meloxicam cohort.

Hard Rule 2 and 6 checks

GI bleeding and anemia are clinical outcomes, not iron deficiency. Iron deficiency anemia is a diagnosis that needs measured iron indices. Confounding by indication is presumed: rheumatoid disease and other chronic inflammation cause anemia independent of the drug, and aspirin or anticoagulant co-use adds bleeding risk.

Counter-evidence held on record

Counter-evidence and confounding The best controlled blood-loss data are near placebo, the label itself names fluid retention (dilution) as one cause of anemia, and the case reports are single patients with other possible contributors (a prior small-bowel resection in [10]). No study compares ferritin before and after starting meloxicam. Framing caution This is a toxicity pathway (blood loss), not an absorption or intake deficiency. New iron deficiency or melena on meloxicam calls for evaluating the bleeding source and the prescription, not an iron supplement by default. No iron dose is recommended here.

Limits on what this shows

• Null findings: No copper measurement in meloxicam users was found, in either direction.

Regulatory status

No copper statement in the meloxicam label sections retrieved [1].

Population evidence

None in humans. Cini 2007 [25] (Tier B, in vitro; PubMed listing text only, abstract not opened): synthesis and crystallography of copper(II) complexes with oxicam NSAIDs, including a meloxicam complex with square-pyramidal coordination, screened for cytotoxicity. Further listing hits describe Cu(II)-meloxicam complexes binding DNA and altering membrane fusion in model systems (not opened, not cited as evidence).

Mechanism

Metal binding by meloxicam is chemically demonstrated in vitro; physiological relevance (plasma concentrations, competition from albumin and ceruloplasmin, effect on absorption or excretion) is not shown.

Counter-evidence held on record

Counter-evidence Metal complexation in a flask does not show depletion; the complexes were studied as synthetic compounds. Framing caution Mechanistic curiosity only. Not a copper deficiency or excess claim and not a reason to supplement or restrict copper. Copper is graded separately from Iron (Hard Rule 7).

Limits on what this shows

• Null findings: The meloxicam-specific rabbit study was essentially null [28]. A dairy cow uterine microbiota study (not gut) also found no meloxicam effect (PubMed listing text only).

Regulatory status

No microbiome statement in the meloxicam label sections retrieved [1].

Population evidence

Meloxicam-specific, Tier B: Eshar and Weese 2014 [28], 6 healthy rabbits, meloxicam 1 mg/kg once daily for 21 days, 16S sequencing of hard feces on days 0, 6, 14 and 21; Firmicutes 82.0 +/- 6.2%, minimal variation, only Proteobacteria changed significantly (P = 0.02); authors concluded no substantial disruption. CLASS EXTRAPOLATION, Tier C: Le Bastard 2018 [29], systematic review of non-antibiotic drugs; NSAIDs showed no significant change in alpha diversity, beta diversity was not significantly altered by NSAIDs, and NSAIDs (with PPIs and metformin) were associated with increases in Gammaproteobacteria (Enterobacter, Escherichia, Klebsiella, Citrobacter) or Enterococcaceae. The abstract does not name the NSAIDs, so meloxicam in the underlying cohorts is unconfirmed. Maseda 2019 [30] (mouse, indomethacin only; listing text) is excluded: meloxicam was not studied.

Mechanism

Plausible in principle through NSAID mucosal injury (label sec 5.2 [1]); not demonstrated for meloxicam in humans.

Class cohort test

Meloxicam inclusion in the class review cohorts could not be confirmed from the abstract, so the class result is Tier C and capped at yellow. Rabbits are hindgut fermenters, so transfer to humans is limited.

Counter-evidence held on record

Counter-evidence The only meloxicam-specific data are null, and the class review found no diversity change. Framing caution Not a dysbiosis claim for meloxicam. No probiotic or other supplement is implied.

Limits on what this shows

• Null findings: In a veterinary observational study of dogs (PubMed listing text only), meloxicam did not cause significant erythrocyte oxidative damage or hemoglobin change, unlike metamizole [31]. A PubMed listing for meloxicam with hemolytic was rate-limited (HTTP 429), the erythrocyte and anemia listings showed no human hemolysis report, and a methemoglobin-specific query was not run, so absence of a hemolysis report is tooling-limited as well as a literature statement.

Regulatory status

Label sec 5.12 (anemia, possible causes, hemoglobin or hematocrit monitoring) [1]. The older label lists anemia at 4.1% and 2.9% in 6-month trials and agranulocytosis, leukopenia, purpura and thrombocytopenia as rare (under 2%) events [2]; these cytopenias are not oxygen-carrying measures.

Population evidence

Han 2025 [9]: nationwide osteoarthritis cohort of 888,909 patients; anemia confirmed among adverse effects across five NSAID subtypes (meloxicam-specific estimate not in the abstract). Case reports of anemia from small-bowel ulceration on meloxicam [10][11]. No hemoglobin, hematocrit, red-cell mass or arterial oxygenation study in meloxicam users with a control group was retrieved.

Mechanism

Per the label: occult or gross blood loss, fluid retention (hemodilution) or an incompletely described effect on erythropoiesis [1]. In vitro, meloxicam inhibited purified human erythrocyte glutathione reductase (IC50 0.029 mM, Ki 0.0061 mM) [24]; no hemolytic consequence has been shown.

Hard Rule 2 check

Anemia is an outcome and is not filed as iron deficiency or as an oxygen-delivery nutrient deficiency. Any effect is mediated by the Iron entry (blood loss) and the Sodium entry (dilution), and is not counted twice.

Counter-evidence held on record

Counter-evidence and confounding Chronic inflammatory disease itself lowers hemoglobin, older arthritis patients carry other bleeding risks, and the anemia incidence in [2] had no retrievable placebo comparator. Framing caution A monitoring prompt (hemoglobin), not a deficiency claim. No supplement is implied.

Limits on what this shows

• Null findings: None found that measured intact-cell ATP for meloxicam. No human fatigue, lactate or energy-status data were located.

Regulatory status

No ATP or energy-metabolism statement in the meloxicam label sections retrieved [1].

Population evidence

None in humans. Moreno-Sanchez 1999 [18]: ATP synthesis was one of three measured endpoints for meloxicam and six other NSAIDs in rat mitochondrial preparations; changes in ATP synthesis varied proportionally with membrane potential across drug concentrations (abstract text as retrieved; concentrations and magnitudes not available). Nadanaciva 2013 [19]: rat liver mitochondrial respiration and hepatocyte panel including meloxicam; results for meloxicam not in the abstract.

Mechanism

Uncoupling lowers the proton gradient that drives ATP synthase, so ATP yield per oxygen consumed falls in isolated preparations [18]. Cellular ATP levels in intact tissue were not shown for meloxicam.

Counter-evidence held on record

Counter-evidence Cells compensate for modest uncoupling, and the protein binding in vivo [1] lowers free drug exposure. The evidence is shared with the Mitochondrial burden entry and is not independent (see Overlap map). Framing caution Do not translate this into a fatigue or low-energy claim for meloxicam users. No supplement is implied.