Article · Wikipedia archive · Last revised Aug 9, 2026

Tolfenamic acid

Tolfenamic acid is a member of the anthranilic acid derivatives class of NSAID drugs. Like other members of the class, it is a COX inhibitor and prevents formation of prostaglandins.

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Aug 9, 2026
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Wikipedia ↗
Tolfenamic acid
Clinical data
Trade namesClotam, Clotan, Tufnil, Migea
AHFS/Drugs.comInternational Drug Names
Routes of
administration		By mouth
ATC code
Legal status
Legal status
  • AU: S4 (Prescription only)
  • EU: Rx-only1
Identifiers
  • 2-[(3-chloro-2-methylphenyl)amino]benzoic acid)2
CAS Number
PubChem CID
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard100.033.862
Chemical and physical data
FormulaC14H12ClNO2
Molar mass261.71 g·mol−1
3D model (JSmol)
  • Clc2cccc(Nc1ccccc1C(=O)O)c2C
  • InChI=1S/C14H12ClNO2/c1-9-11(15)6-4-8-12(9)16-13-7-3-2-5-10(13)14(17)18/h2-8,16H,1H3,(H,17,18) checkY
  • Key:YEZNLOUZAIOMLT-UHFFFAOYSA-N checkY
 X markNcheckY (what is this?)  (verify)

Tolfenamic acid is a member of the anthranilic acid derivatives (or fenamate) class of NSAID drugs.3 Like other members of the class, it is a COX inhibitor and prevents formation of prostaglandins.4

It is used in the UK as a treatment for migraine.56 It is generally not available in the US.4 It is available in some Asian, Latin American and European countries as a generic drug for humans and for animals.7

Medical uses

Tolfenamic acid is used in the prevention and treatment of conditions associated with pain and inflammation.89 However, despite its efficacy when administered intramuscularly, subcutaneously, or orally,10 TFA-based drugs have not yet gained approval in the United States and some other countries due to the significant number of reported side effects.1112

Chemistry

Tolfenamic acid, belonging to the pharmacological group of fenamates, possesses a chemical structure typical of anthranilic acid derivatives. In this structure, one of the hydrogen atoms of the nitro group is substituted by a benzene ring substituted with a methyl group in the ortho position and a chlorine atom in the meta position."13

Nine forms of tolfenamic acid have been identified, some of which are determined by conformational states.141516 These polymorphic forms exhibit variations in the spatial arrangement within the unit cell and in the values of the C-N(H)-C-C angle.16 This diversity in solid forms makes TFA an attractive candidate for modification and utilization in medical applications.

History

It was discovered by scientists at Gea Pharmaceutical Company in Denmark.3

Research

Tolfenamic acid has demonstrated antiproliferative effects against pancreatic, sigmoid-colon, and rectal cancer cell lines in preclinical studies.17

References

References

  1. "Tolfenamic acid VMD". European Medicines Agency (EMA). 5 December 2024. Retrieved 6 December 2024.
  2. Andersen KV, Larsen S, Alhede B, Gelting N, Buchardt O (1989). "Characterization of two polymorphic forms of tolfenamic acid, N-(2-methyl-3-chlorophenyl)anthranilic acid: their crystal structures and relative stabilities". J. Chem. Soc., Perkin Trans. 2 (10): 1443–1447. doi:10.1039/P29890001443.
  3. Pentikäinen PJ, Neuvonen PJ, Backman C (1981). "Human pharmacokinetics of tolfenamic acid, a new anti-inflammatory agent". European Journal of Clinical Pharmacology. 19 (5): 359–365. doi:10.1007/bf00544587. PMID 7238564. S2CID 9428076.
  4. NIH LiverTox Database Mefenamic Acid Last updated June 23, 2015. Page accessed July 3, 2015. Quote: "(fenamates generally not available in the United States, such as tolfenamic acid and flufenamic acid)"
  5. NHS Tolfenamic Acid (Tolfenamic acid 200mg tablets) Page accessed July 3, 2015
  6. "Virtual Medicinal Product (VMP) - Tolfenamic acid 200mg tablets - dm+d browser". dmd-browser.nhsbsa.nhs.uk. Retrieved 23 April 2024.
  7. Drugs.com Drugs.com international listings for tolfenamic acid Page accessed July 3, 2015
  8. Kajander A, Laine V, Gothoni G (January 1972). "Effect of tolfenamic acid in rheumatoid arthritis". Scandinavian Journal of Rheumatology. 1 (2): 91–93. doi:10.3109/03009747209103003. PMID 4572954.
  9. Basha R, Baker CH, Sankpal UT, Ahmad S, Safe S, Abbruzzese JL, et al. (January 2011). "Therapeutic applications of NSAIDS in cancer: special emphasis on tolfenamic acid". Frontiers in Bioscience. 3 (2): 797–805. doi:10.2741/s188. PMID 21196413.
  10. Corum O, Corum DD, Er A, Yildiz R, Uney K (December 2018). "Pharmacokinetics and bioavailability of tolfenamic acid in sheep". Journal of Veterinary Pharmacology and Therapeutics. 41 (6): 871–877. doi:10.1111/jvp.12702. PMID 30084126. S2CID 51930602.
  11. Kjaersgård Rasmussen MJ, Holt Larsen B, Borg L, Soelberg Sørensen P, Hansen PE (June 1994). "Tolfenamic acid versus propranolol in the prophylactic treatment of migraine". Acta Neurologica Scandinavica. 89 (6): 446–450. doi:10.1111/j.1600-0404.1994.tb02664.x. PMID 7976233. S2CID 12334561.
  12. Isomäki H (October 1994). "Tolfenamic acid: clinical experience in rheumatic diseases". Pharmacology & Toxicology. 75 (s2): 64–65. doi:10.1111/j.1600-0773.1994.tb02001.x. PMID 7816786.
  13. López-Mejías V, Kampf JW, Matzger AJ (April 2009). "Polymer-induced heteronucleation of tolfenamic acid: structural investigation of a pentamorph". Journal of the American Chemical Society. 131 (13): 4554–4555. Bibcode:2009JAChS.131.4554L. doi:10.1021/ja806289a. PMC 2729806. PMID 19334766.
  14. Belov KV, Dyshin AA, Krestyaninov MA, Efimov SV, Khodov IA, Kiselev MG (December 2022). "Conformational preferences of tolfenamic acid in DMSO-CO2 solvent system by 2D NOESY". Journal of Molecular Liquids. 367 120481. doi:10.1016/j.molliq.2022.120481. S2CID 252630985.
  15. SeethaLekshmi S, Guru Row TN (1 August 2012). "Conformational Polymorphism in a Non-steroidal Anti-inflammatory Drug, Mefenamic Acid". Crystal Growth & Design. 12 (8): 4283–4289. Bibcode:2012CrGrD..12.4283S. doi:10.1021/cg300812v. ISSN 1528-7483.
  16. Case DH, Srirambhatla VK, Guo R, Watson RE, Price LS, Polyzois H, et al. (5 September 2018). "Successful Computationally Directed Templating of Metastable Pharmaceutical Polymorphs". Crystal Growth & Design. 18 (9): 5322–5331. Bibcode:2018CrGrD..18.5322C. doi:10.1021/acs.cgd.8b00765. ISSN 1528-7483.
  17. Kim JH, Jung JY, Shim JH, Kim J, Choi KH, Shin JA, et al. (July 2010). "Apoptotic Effect of Tolfenamic Acid in KB Human Oral Cancer Cells: Possible Involvement of the p38 MAPK Pathway". Journal of Clinical Biochemistry and Nutrition. 47 (1): 74–80. doi:10.3164/jcbn.10-02. PMC 2901767. PMID 20664734.
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