Title: Flupirtine
CAS Registry Number: 56995-20-1
CAS Name: [2-Amino-6-[[(4-fluorophenyl)methyl]amino]-3-pyridinyl]carbamic acid ethyl ester
Additional Names: 2-amino-6-[(p-fluorobenzyl)amino]-3-pyridinecarbamic acid ethyl ester
Trademarks: D-9998
Molecular Formula: C15H17FN4O2
Molecular Weight: 304.32
Percent Composition: C 59.20%, H 5.63%, F 6.24%, N 18.41%, O 10.51%
Literature References: Substituted pyridine with central analgesic properties. Prepn: K. Thiele, W. von Bebenburg, ZA 6902364 (1970 to Degussa); W. von Bebenburg et al., Chem. Ztg. 103, 387 (1979); eidem, ibid. 105, 217 (1981). Prepn of maleate: W. von Bebenburg, S. Pauluhn, BE 890331; eidem, US 4481205 (1980, 1984 both to Degussa). Comparison of pharmacology with other analgesics: V. Jakovlev et al., Arzneim.-Forsch. 35, 30 (1985). Pharmacokinetic studies: K. Obermeier et al., ibid. 60. Effect on driving ability: B. Biehl, ibid. 77. Clinical trials in treatment of cancer pain: W. Scheef, D. Wolf-Gruber, ibid. 75. Efficacy in treatment of pain after hysterectomy: R. A. Moore et al., Br. J. Anaesth. 55, 429 (1983). Symposium on pharmacology and clinical efficacy: Postgrad. Med. J. 63, Suppl. 3, 1-113 (1987).
Properties: Crystals from isopropanol, mp 115-116°. 5% ethanol soln is colorless, turns green on exposure to air for 20 hours. LD50 orally in mice, rats: 617, 1660 mg/kg (Jakovlev).
Melting point: mp 115-116°
Toxicity data: LD50 orally in mice, rats: 617, 1660 mg/kg (Jakovlev)
Derivative Type: Hydrochloride
Molecular Formula: C15H17FN4O2.HCl
Molecular Weight: 340.78
Percent Composition: C 52.87%, H 5.32%, F 5.57%, N 16.44%, O 9.39%, Cl 10.40%
Properties: Crystals from water, mp 214-215°. When prepd industrially contains intensely blue by-product.
Melting point: mp 214-215°
Derivative Type: Maleate
CAS Registry Number: 75507-68-5
Trademarks: Katadolon (AWD)
Molecular Formula: C15H17FN4O2.C4H4O4
Molecular Weight: 420.39
Percent Composition: C 54.28%, H 5.04%, F 4.52%, N 13.33%, O 22.84%
Properties: Colorless crystals from isopropanol, mp 175.5-176°. Formed as mixture of two crystalline forms A and B; mixtures containing 60-90% A are preferred.
Melting point: mp 175.5-176°
Therap-Cat: Analgesic.
Keywords: Analgesic (Non-Narcotic).
Fluprednidene Acetate Fluprednisolone Fluproquazone Fluprostenol Flupyrsulfuron-methyl

Systematic (IUPAC) name
ethyl {2-amino-6-[(4-fluorobenzyl)amino]pyridin-3-yl}carbamate
Clinical data
AHFS/Drugs.com International Drug Names
Legal status  ?
Pharmacokinetic data
Bioavailability 90% (oral), 70% (rectal)[1]
Metabolism Hepatic to 2-amino-3-acetylamino-6-(para-fluorobenzylamino) pyridine (which has 20-30% the analgesic potential of its parent compound) and Para-fluorohippuric acid.[2]
Half-life 6.5 hrs (average), 11.2-16.8 hrs (average 14 hrs) (elderly), 8.7-10.9 hrs (average 9.8 hrs) (in those with moderate-level renal impairment)


Excretion 72% of flupirtine and its metabolites appear in urine and 18% appear in faeces.[3]
CAS number 56995-20-1 N
ATC code N02BG07
PubChem CID 53276
IUPHAR ligand 2598
ChemSpider 48119 N
KEGG D07978 YesY
Chemical data
Formula C15H17FN4O2 
Mol. mass 304.32 g/mol
 N (what is this?)  (verify)

Flupirtine is an aminopyridine that functions as a centrally acting non-opioid analgesic. It first became available in Europe in 1984, and is sold mainly under the names Katadolon, Trancolong, Awegal, Efiret, Trancopal Dolo, and Metanor.[4] Flupirtine is sold by Intas Pharma under the brand name Pruf in India. It is unique as a non-opioid, non-NSAID, non-steroidal analgesic. In 2010 the chemically related drug (the difference being that the pyridine group in flupirtine is replaced with a phenyl group) retigabine (INN; ezogabine [USAN]) was approved by the FDA as an anticonvulsant for the treatment of partial seizures. Retigabine also works by opening the neuronal KCNQ/Kv7 potassium channel, just like flupirtine.