Racephedrine

Racephedrine, also known as racemic ephedrine and sold under the brand names Efetonina and Ephoxamine among others, is the racemic form of ephedrine which has been used as a bronchodilator to treat asthma.^{[1][2][3][4][5]} More specifically, it is a racemic mixture of (1R,2S)- and (1S,2R)-enantiomers.^[3] Conversely, ephedrine is the enantiopure (1R,2S)-enantiomer.^[1] Racephedrine has been marketed for medical use in Italy.^[1] Like ephedrine, racephedrine is a releasing agent of norepinephrine and to a much lesser extent of dopamine.^[6][7][8][9] Both ephedrine enantiomers are active in this regard, but ephedrine ((1R,2S)-ephedrine) has greater potency than (1S,2R)-ephedrine.^[6][7][8][9]

Monoamine release by ephedrine and related agents (EC₅₀Tooltip half maximal effective concentration, nM)^[6][7]

Compound	NETooltip Norepinephrine	DATooltip Dopamine	5-HTTooltip Serotonin	Ref
Dextroamphetamine (S(+)-amphetamine)	6.6–7.2	5.8–24.8	698–1765	[8][10]
S(–)-Cathinone	12.4	18.5	2366	[9]
Ephedrine ((–)-ephedrine; (1R,2S)-ephedrine)	43.1–72.4	236–1350	>10000	[8]
(+)-Ephedrine ((1S,2R)-ephedrine)	218	2104	>10000	[8][9]
Dextromethamphetamine (S(+)-methamphetamine)	12.3–13.8	8.5–24.5	736–1291.7	[8][11]
Levomethamphetamine (R(–)-methamphetamine)	28.5	416	4640	[8]
(+)-Phenylpropanolamine ((+)-norephedrine)	42.1	302	>10000	[9]
(–)-Phenylpropanolamine ((–)-norephedrine)	137	1371	>10000	[9]
Cathine ((+)-norpseudoephedrine)	15.0	68.3	>10000	[9]
(–)-Norpseudoephedrine	30.1	294	>10000	[9]
(–)-Pseudoephedrine	4092	9125	>10000	[9]
Pseudoephedrine ((+)-pseudoephedrine)	224	1988	>10000	[9]
The smaller the value, the more strongly the substance releases the neurotransmitter. See also Monoamine releasing agent § Activity profiles for a larger table with more compounds.

Racephedrine

(−)-(1R,2S)-ephedrine (top), (+)-(1S,2R)-ephedrine (bottom)
Clinical data
Trade names	Efetonina; Ephoxamine
Other names	Racemic ephedrine; (±)-Ephedrine; dl-Ephedrine; (1RS,2SR)-Ephedrine
Drug class	Norepinephrine releasing agent; Sympathomimetic; Bronchodilator; Psychostimulant
Identifiers
IUPAC name 2-(methylamino)-1-phenylpropan-1-ol
CAS Number	90-81-3
PubChem CID	5032
DrugBank	DB14752
ChemSpider	4856
UNII	03VRY66076
KEGG	C22822
ChEMBL	ChEMBL279157
Chemical and physical data
Formula	C10H15NO
Molar mass	165.236 g·mol−1
3D model (JSmol)	Interactive image
SMILES CC(C(C1=CC=CC=C1)O)NC
InChI InChI=1S/C10H15NO/c1-8(11-2)10(12)9-6-4-3-5-7-9/h3-8,10-12H,1-2H3 Key:KWGRBVOPPLSCSI-UHFFFAOYSA-N

Racephedrine has been used in a variety of combination drugs with other agents, including theophylline, aminophylline, oxtriphylline, phenobarbital, pentobarbital, pyrilamine, phenacetin, salicylamide, ascorbic acid, and opium, among others.^[12] Brand names of these combination preparations have included Amiphedrin, Amodrine, Amodrine E C, Asphamal-D, Asthmadrin, Cenamal, Cholarace, Phedrahist, Respirol, Salidin, Synate-M, and Synophedal.^[12]

See also

• Hydroxymethylamphetamine