Methylephedrine
Chemical compound
From Wikipedia, the free encyclopedia
Methylephedrine, sold under the brand name Metheph among others, is a sympathomimetic medication described as an antiasthmatic agent and used to treat coughing and nasal congestion.[3][4][1] It is reported to be used in various over-the-counter cough and cold preparations throughout the world, including Japan.[1]
• Ephedrine[1][2]
• Norephedrine[1][2]
| |
| Clinical data | |
|---|---|
| Trade names | Metheph, Methy-F, Tybraine |
| Other names | N-Methylephedrine; N-Methyl-(–)-ephedrine; L-Methylephedrine; N-Methyl-L-ephedrine; (−)-N-Methylephedrine; N,N-Dimethylnorephedrine |
| Drug class | Sympathomimetic; Norepinephrine releasing agent; Bronchodilator; Nasal decongestant; Antitussive |
| Pharmacokinetic data | |
| Metabolites | • Methylephedrine N-oxide[1][2] • Ephedrine[1][2] • Norephedrine[1][2] |
| Excretion | Urine[1] |
| Identifiers | |
| |
| CAS Number | |
| PubChem CID | |
| DrugBank | |
| ChemSpider | |
| UNII | |
| KEGG | |
| ChEBI | |
| ChEMBL | |
| CompTox Dashboard (EPA) | |
| ECHA InfoCard | 100.008.203 |
| Chemical and physical data | |
| Formula | C11H17NO |
| Molar mass | 179.263 g·mol−1 |
| 3D model (JSmol) | |
| |
| |
The drug is an ephedrine-like sympathomimetic and activates α- and β-adrenergic receptors.[5] Chemically, it is a substituted amphetamine and is closely related to ephedrine.[3][4]
Methylephedrine was discovered by 1927.[6] It is mostly no longer marketed as a prescription drug.[4] The drug is also found naturally as an alkaloid in Ephedra species including Ephedra sinica, Ephedra vulgaris, and Ephedra distachya.[3][6]
Side effects
Rarely, heart failure and stroke in association with use of methylephedrine have been reported.[7][8][9]
Methylephedrine shows reinforcing effects, a measure of addiction and misuse potential, in monkeys.[10]
Pharmacology
Pharmacodynamics
Methylephedrine is a sympathomimetic and ephedrine-like agent.[5][1] Ephedrine and related agents act as norepinephrine releasing agents and hence as indirectly acting sympathomimetics.[1] In relation to this, methylephedrine stimulates α- and β-adrenergic receptors.[5][1] The drug has bronchodilator and nasal decongestant effects.[5]
The occupancy of the dopamine transporter (DAT) by racemic methylephedrine has been studied.[11]
Pharmacokinetics
Methylephedrine is metabolized into ephedrine and norephedrine.[1][2] It is excreted in urine 33 to 40% unchanged, 15% as methylephedrine N-oxide, and 8% as ephedrine after 24 hours.[1][2]
Chemistry
Methylephedrine, also known as (1R,2S)-β-hydroxy-N,N-dimethyl-α-methyl-β-phenethylamine and as (1R,2S)-β-hydroxy-N,N-dimethylamphetamine, is a substituted phenethylamine and amphetamine derivative.[3][4] It is the N-methylated derivative of ephedrine ((1R,2S)-β-hydroxy-N-methylamphetamine).[3][4]
A closely related compound and stereoisomer of methylephedrine is N-methylpseudoephedrine.[3] Another related analogue is dimethylamphetamine (N,N-dimethylamphetamine), which is said to be a prodrug of methamphetamine and/or amphetamine.[12] Other analogues include etafedrine (N-ethylephedrine) and cinnamedrine (N-cinnamylephedrine).[3]
The experimental log P of methylephedrine is 2.47 and its predicted log P ranges from 1.7 to 1.74.[13][1][14]
In organic chemistry, N-methylephedrine is used as a resolving agent and as a precursor to chiral supporting electrolytes, phase-transfer catalysts, and reducing agents.[15]
History
Society and culture
Names
Methylephedrine is the generic name of the drug and its BAN.[3][4][16] In the case of the hydrochloride salt, its generic name is methylephedrine hydrochloride and this is its BANM.[3][4][16] Brand names of methylephedrine include Metheph, Methy-F, and Tybraine, among others.[3][4][16]
Recreational use
Similarly to ephedrine, methylephedrine may have misuse potential.[1][17] The drug shows reinforcing effects in monkeys.[10] It is one of the four constituents of BRON, a Japanese over-the-counter cough medicine with reports of misuse.[1][17] However, addiction liability of BRON was attributed primarily to the codeine component.[17] A case report of addiction to methylephedrine exists.[9]
Use in sports and exercise
Methylephedrine is on the World Anti-Doping Agency's prohibited list.[5]