Mesocarb (brand names Sidnocarb, Sydnocarb) is a drug that is currently being developed for

Parkinson's disease Parkinson's disease (PD), or simply Parkinson's, is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms becom ...

. The drug was originally developed in the

USSR The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nationa ...

in the 1970s for a variety of indications including

asthenia Weakness is a symptom of a number of different conditions. The causes are many and can be divided into conditions that have true or perceived muscle weakness. True muscle weakness is a primary symptom of a variety of skeletal muscle diseases, i ...

apathy Apathy is a lack of feeling, emotion, interest, or concern about something. It is a state of indifference, or the suppression of emotions such as concern, excitement, motivation, or passion. An apathetic individual has an absence of intere ...

adynamia Adynamia means lack of strength or vigor due to a pathological condition. It is often associated with a range of neurological diseases such as multiple sclerosis and medial-frontal lobe The frontal lobe is the largest of the four major lobes ...

and some clinical aspects of depression and

schizophrenia Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social wit ...

. Mesocarb was used for counteracting the sedative effects of benzodiazepine drugs, increasing workload capacity and cardiovascular function, treatment of ADHD and hyperactivity in children, as a

nootropic Nootropics ( , or ) (colloquial: smart drugs and cognitive enhancers, similar to adaptogens) are a wide range of natural or synthetic dietary supplement, supplements or drugs and other substances that are claimed to improve cognitive function ...

, and as a drug to enhance resistance to extremely cold temperatures. It is also listed as having antidepressant and anticonvulsant properties. The drug has been found to act as a selective

dopamine reuptake inhibitor A dopamine reuptake inhibitor (DRI) is a class of drug which acts as a reuptake inhibitor of the monoamine neurotransmitter dopamine by blocking the action of the dopamine transporter (DAT). Reuptake inhibition is achieved when extracellular dop ...

by blocking the actions of the dopamine transporter (DAT), and lacks the dopamine release characteristic of stimulants such as

dextroamphetamine Dextroamphetamine is a central nervous system (CNS) stimulant and an amphetamine enantiomer that is prescribed for the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. It is also used as an athletic performance an ...

. It was the most selective DAT inhibitor amongst an array of other DAT inhibitors to which it was compared. Mesocarb was sold in

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...

as 5 milligram tablets under the brand name Sydnocarb. Hydroxylated metabolites can be detected in urine for up to 10 days after consumption. The drug is almost unknown in the western world and is neither used in medicine nor studied scientifically to any great extent outside Russia and other countries in the former Soviet Union. It has however been added to the list of drugs under international control and is a scheduled substance in most countries, despite its multiple therapeutic applications and reported lack of significant

abuse potential Substance abuse, also known as drug abuse, is the use of a drug in amounts or by methods which are harmful to the individual or others. It is a form of substance-related disorder. Differing definitions of drug abuse are used in public health, ...

. Mesocarb had erroneously been referred to as a prodrug of amphetamine but this was based on older literature that relied on gas chromatography as an analytical method. Subsequently, with the advent of mass spectroscopy, it has been shown that presence of amphetamine in prior studies was an artifact of gas chromatography method. More recent studies using mass spectroscopy show that negligible levels of amphetamine are released from mesocarb metabolism.

Chemistry

Mesocarb is a

mesoionic In chemistry, mesoionic compounds are one in which a heterocyclic structure is dipolar and where both the negative and the positive charges are delocalized. A completely uncharged structure cannot be written and mesoionic compounds cannot be rep ...

sydnone imine Sydnone imine is a mesoionic heterocyclic aromatic chemical compound. Sydnone imine is the imine of sydnone where the keto functional group of sydnone (=O) has been replaced with an imine (=NH) group. A sydnone imine substructure can be found ...

. It has the amphetamine-backbone present, except that the ''R''_N has a complicated imine side-chain present.

Preparation

References

{{Monoamine reuptake inhibitors Dopamine reuptake inhibitors Oxadiazoles Prodrugs Russian drugs Stimulants Ureas Drugs in the Soviet Union