Title: Eperisone
CAS Registry Number: 64840-90-0
CAS Name: 1-(4-Ethylphenyl)-2-methyl-3-(1-piperidinyl)-1-propanone
Additional Names: 4¢-ethyl-2-methyl-3-piperidinopropiophenone
Molecular Formula: C17H25NO
Molecular Weight: 259.39
Percent Composition: C 78.72%, H 9.71%, N 5.40%, O 6.17%
Literature References: Spasmolytic agent related structurally to tolperisone, q.v. Prepn: E. Morita et al., DE 2458638; E. Morita, T. Kanai, US 4181803 (1975, 1980 both to Eisai). Pharmacological study: K. Tanaka et al., Nippon Yakurigaku Zasshi 77, 511 (1981), C.A. 95, 35471t (1981). Absorption, distribution, excretion in rats and guinea pigs: T. Fujita et al., Oyo Yakuri 21, 835 (1981), C.A. 96, 28193w (1982). Toxicity study: H. Miyagawa et al., ibid. 939, C.A. 96, 79722a (1982).
Derivative Type: Hydrochloride
CAS Registry Number: 56839-43-1
Additional Names: EMPP
Manufacturers' Codes: E-646
Trademarks: Mional (Eisai); Myonal (Eisai)
Molecular Formula: C17H25NO.HCl
Molecular Weight: 295.85
Percent Composition: C 69.02%, H 8.86%, N 4.73%, O 5.41%, Cl 11.98%
Properties: Needles from isopropanol, mp 170-172°. LD50 in male S.D. rats, Wistar rats, mice (mg/kg): 1300, 1850, 1024 orally (Miyagawa).
Melting point: mp 170-172°
Toxicity data: LD50 in male S.D. rats, Wistar rats, mice (mg/kg): 1300, 1850, 1024 orally (Miyagawa)
Therap-Cat: Muscle relaxant (skeletal).
Keywords: Muscle Relaxant (Skeletal).
Epiandrosterone Epichlorohydrin Epicholestanol Epicholesterol Epicillin

Systematic (IUPAC) name
Clinical data
AHFS/Drugs.com International Drug Names
Legal status not licensed
Routes O
CAS number 56839-43-1 N
ATC code M03BX09
PubChem CID 3236
ChemSpider 3123 YesY
UNII 2M2P0551D3 YesY
KEGG D01671 YesY
Chemical data
Formula C17H25NO 
Mol. mass 259.387 g/mol
 N (what is this?)  (verify)

Eperisone (formulated as the eperisone hydrochloride salt) is an antispasmodic drug.

Eperisone acts by relaxing both skeletal muscles and vascular smooth muscles, and demonstrates a variety of effects such as reduction of myotonia, improvement of circulation, and suppression of the pain reflex. The drug inhibits the vicious circle of myotonia by decreasing pain, ischaemia, and hypertonia in skeletal muscles, thus alleviating stiffness and spasticity, and facilitating muscle movement[1]

Eperisone also improves dizziness and tinnitus associated with cerebrovascular disorders or cervical spondylosis.

Eperisone has a relatively low incidence of sedation when compared with other antispasmodic drugs; this simplifies the clinical application of the drug and makes it an attractive choice for patients who require antispasmodic therapy without a reduction in alertness.

Japanese package of eperisone

Eperisone also facilitates voluntary movement of the upper and lower extremities without reducing muscle power; it is therefore useful during the initial stage of rehabilitation and as a supporting drug during subsequent rehabilitative therapy.