Dimethocaine

Dimethocaine is a local anesthetic that, because of its similarity in action to cocaine, has potential for abuse. This compound completely inhibits dopamine uptake in rat striatal synaptosomes with an IC50 value of 1.2 µM comparable to that of cocaine (IC50 = 0.7 µM).1 As a result, dimethocaine dose-dependently substitutes for cocaine in drug discrimination tests in rats and rhesus monkeys.2,3 This product is intended for forensic and research purposes.

Technical Information

Formal Name 3-(diethylamino)-2,2-dimethyl-1-(4-aminobenzoate)-1-propanol, monohydrochloride

CAS Number 553-63-9

Molecular Formula C16H26N2O2 • HCl

Formula Weight     314.9

Purity     ≥98%

Formulation A crystalline solid

It was originally synthesized by the Hoffmann-La Roche company in 1930. It was sold under the market name larocaine. During the 1930s dimethocaine gained popularity in the US as a local anesthetic. Just like cocaine and procaine, it was used during surgery, primarily in dentistry, ophthalmology and otolaryngology. However, in the 1940s, it was removed from the market because of its psychoactive effects and risk of addiction. Nowadays dimethocaine is abused for these psychoactive effects. It is sold as a cocaine surrogate to circumvent legislation issues.

Dimethocaine and structurally related local anesthetics like cocaine and procaine are suggested to inhibit the uptake of dopamine (DA) by blocking dopamine transporters (DAT). The dopamine transporter controls the dynamics of the neurotransmitter dopamine. This neurotransmitter controls many functions including movement, cognition and mood. Drug like cocaine and dimethocaine induce dopamine overflow by inhibiting dopamine transporters and thus creating a euphoric effect. In addition to inhibiting dopamine uptake, dimethocaine was also shown to inhibit the binding of CFT, a different dopamine uptake inhibitor.These inhibitory properties are responsible for the stimulatory effects of dimethocaine on the central nervous system. Both in vivo and in vitro measurements of dopamine transporter activity showed that dimethocaine is a potent and efficacious dopaminergic antagonist. These effects were mainly observed in the nucleus accumbens, a region in the basal forebrain. Comparison of the pharmacological potencies of different local anesthetics revealed the following potency order