Meloxicam
[CAS# 71125-38-7]

Identification

• Classification: API >> Antipyretic analgesics >> Non-steroidal anti-inflammatory drugs
• Name: Meloxicam
• Synonyms: 4-Hydroxy-2-methyl-N-(5-methyl-1,3-thiazol-2-yl)-2H-1,2-benzothiazin-3-crboxamide 1,1-dioxide
• Molecular Formula: C₁₄H₁₃N₃O₄S₂
• Molecular Weight: 351.40
• CAS Registry Number: 71125-38-7
• EC Number: 615-253-8
• SMILES: CC1=CN=C(S1)NC(=O)C2=C(C3=CC=CC=C3S(=O)(=O)N2C)O

Properties

• Density: 1.6±0.1 g/cm³ Calc.^*
• Solubility: DMSO 30 mg/mL, Water $lessThan$1 mg/mL (Expl.)
• Index of refraction: 1.72 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS06;GHS08 Danger
• Risk Statements: H301-H360-H412
• Safety Statements: P203-P264-P270-P273-P280-P301+P316-P318-P321-P330-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	3	H301
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Reproductive toxicity	Repr.	1A	H360
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Reproductive toxicity	Repr.	1B	H360
Reproductive toxicity	Repr.	2	H361
Specific target organ toxicity - repeated exposure	STOT RE	1	H372
Specific target organ toxicity - single exposure	STOT SE	1	H370
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	4	H332
Specific target organ toxicity - single exposure	STOT SE	3	H336
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H412
Reproductive toxicity	Repr.	2	H360
Reproductive toxicity	Repr.	1A	H360FD
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	4	H301
Acute toxicity	Acute Tox.	3	H331
Reproductive toxicity	Lact.	-	H362
Acute toxicity	Acute Tox.	3	H311
Acute toxicity	Acute Tox.	2	H300

Discovery and Applications

Meloxicam is a nonsteroidal anti-inflammatory drug (NSAID) that belongs to the oxicam class. It is used for the treatment of inflammatory and painful conditions such as osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis. Meloxicam exhibits preferential inhibition of cyclooxygenase-2 (COX-2) over cyclooxygenase-1 (COX-1), a property that distinguishes it from many traditional NSAIDs and contributes to its gastrointestinal safety profile. This selective inhibition reduces the synthesis of prostaglandins, which are mediators of inflammation and pain.

Meloxicam was developed and introduced by Boehringer Ingelheim in the early 1990s as part of an effort to discover NSAIDs with improved tolerability. Its structure is based on the enolic acid framework characteristic of the oxicam family. The chemical name of meloxicam is 4-hydroxy-2-methyl-N-(5-methyl-2-thiazolyl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide. It has a molecular formula of C14H13N3O4S2 and is commonly formulated as meloxicam tablets, oral suspensions, or injectable solutions.

Meloxicam’s pharmacological activity is largely attributed to its ability to inhibit COX-2, the isoenzyme induced during inflammation. Unlike COX-1, which is constitutively expressed and involved in protective physiological functions such as gastric mucosa maintenance, COX-2 is upregulated in response to inflammatory stimuli. The selectivity of meloxicam for COX-2 contributes to its effectiveness in reducing pain and swelling while mitigating some of the gastrointestinal side effects linked to non-selective NSAIDs.

Meloxicam is indicated for the symptomatic treatment of osteoarthritis and rheumatoid arthritis in adults. It is also approved for use in ankylosing spondylitis, a chronic inflammatory disease of the axial skeleton. The drug is administered orally, usually once daily, due to its long elimination half-life of approximately 15 to 20 hours. This dosing convenience enhances patient adherence in chronic treatment regimens. Meloxicam has also been studied and approved in veterinary medicine for use in dogs and cats to manage musculoskeletal disorders and postoperative pain.

In clinical trials, meloxicam has demonstrated efficacy comparable to other NSAIDs in reducing joint tenderness, swelling, and stiffness associated with arthritis. It has shown a more favorable gastrointestinal profile compared to drugs such as piroxicam and diclofenac, as evidenced by a lower incidence of endoscopic gastric lesions and dyspepsia. Nonetheless, meloxicam, like all NSAIDs, carries risks including gastrointestinal ulceration, renal impairment, and cardiovascular events. The cardiovascular safety of meloxicam has been examined in observational studies, with findings suggesting a relatively lower risk compared to some other selective and non-selective NSAIDs, though caution is still warranted, especially in patients with existing cardiovascular conditions.

Adverse effects commonly associated with meloxicam include abdominal pain, nausea, diarrhea, headache, dizziness, and edema. Rare but serious events such as gastrointestinal bleeding, hepatotoxicity, and hypersensitivity reactions have also been reported. The use of meloxicam is contraindicated in individuals with known hypersensitivity to the drug, history of asthma or allergic-type reactions after taking aspirin or other NSAIDs, and in patients with active gastrointestinal bleeding or ulceration.

Meloxicam is metabolized primarily in the liver by cytochrome P450 enzymes, particularly CYP2C9 and to a lesser extent CYP3A4, and is excreted in urine and feces as inactive metabolites. Dose adjustments may be necessary in patients with hepatic or renal impairment. Concomitant use with other nephrotoxic or anticoagulant agents should be approached with caution.

Meloxicam remains a widely prescribed NSAID, valued for its balance of efficacy and tolerability in the management of chronic inflammatory joint diseases. Its once-daily dosing and favorable gastrointestinal profile have supported its continued use in clinical practice across various populations and settings.

References

2012. Preferential accumulation of meloxicam in inflamed synovial joints of dogs. The Veterinary record, 170(8).
DOI: 10.1136/vr.100306

2007. Radiosensitizing potential of the selective cyclooygenase-2 (COX-2) inhibitor meloxicam on human glioma cells. Journal of Neuro-Oncology, 85(1).
DOI: 10.1007/s11060-007-9385-4

2000. Safety and efficacy of meloxicam in the treatment of osteoarthritis: a 12-week, double-blind, multiple-dose, placebo-controlled trial. The Meloxicam Osteoarthritis Investigators. Archives of Internal Medicine, 160(19).
DOI: 10.1001/archinte.160.19.2947