4-Methylmethamphetamine (4-MMA), also known as mephedrine, is a putative stimulant and entactogen drug of the amphetamine family. It acts as a serotonin–norepinephrine–dopamine releasing agent (SNDRA). The drug is the β-diketone analogue of mephedrone (4-methylmethcathinone; 4-MMC) and the N-methyl analogue of 4-methylamphetamine (4-MA).
Pharmacology Pharmacodynamics 4-MMA acts as a potent and well-balanced serotonin–norepinephrine–dopamine releasing agent (SNDRA). It induces hyperlocomotion and stereotypy (psychostimulant-like effects) as well as hyperthermia in mice, similarly to methcathinone.
+ Compound Ref Dextroamphetamine 6.6–10.2 5.8–24.8 698–1,765 Dextromethamphetamine 12.3–14.3 8.5–40.4 736–1,292 4-Methylamphetamine 22.2 44.1 53.4 4-Methylmethamphetamine (mephedrine) 66.9 41.3 67.4 4-Methylethylamphetamine 182 550 102 4-Methylpropylamphetamine 752 650 4-Methylbutylamphetamine 4-Methylmethcathinone (mephedrone) 58–62.7 49.1–51 118.3–122 Notes: The smaller the value, the more strongly the drug releases the neurotransmitter. The assays were done in rat brain synaptosomes and human potencies may be different. See also Monoamine releasing agent § Activity profiles for a larger table with more compounds. Refs:
Dopaminergic neurotoxicity In contrast to methamphetamine and methcathinone, 4-MMA appears to produce minimal dopaminergic neurotoxicity in mice. Conversely, mephedrone shows no dopaminergic neurotoxicity at all in mice. It was theorized that 4-methyl and β-keto substitutions on amphetamines may result in loss of activity at the vesicular monoamine transporter 2 (VMAT2), loss of elevations of cytosolic dopamine concentrations, and consequent loss of dopaminergic neurotoxic potential. Accordingly, the dopaminergic neurotoxicity of 4-MMA was greatly enhanced by the dopamine precursor levodopa (L-DOPA), the monoamine oxidase inhibitor (MAOI) pargyline, and methamphetamine (a VMAT2 inhibitor/reverser), all of which are known to increase the cytosolic pool of dopamine. However, in contrast to 4-MMA, the dopaminergic neurotoxicity of methcathinone was enhanced only by levodopa and that of mephedrone was enhanced only by methamphetamine.
See also Substituted amphetamine 3-Methylmethamphetamine (3-MMA) 3-Methoxymethamphetamine (MMMA) 4-Methoxymethamphetamine (PMMA) 4-Fluoromethamphetamine (4-FMA)
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