Mesocarb (brand names Sidnocarb, Sydnocarb) is a

drug A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via insuffla ...

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

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 of ...

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 withdra ...

. Mesocarb was used for counteracting the sedative effects of

benzodiazepine Benzodiazepines (BZD, BDZ, BZs), sometimes called "benzos", are a class of depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat conditions such as anxiety disorders, ...

drugs, increasing workload capacity and cardiovascular function, treatment of

ADHD Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by excessive amounts of inattention, hyperactivity, and impulsivity that are pervasive, impairing in multiple contexts, and otherwise age-inapp ...

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 supplements or drugs and other substances that are claimed to improve cognitive function or to promote re ...

, and as a drug to enhance resistance to extremely cold temperatures. It is also listed as having

antidepressant Antidepressants are a class of medication used to treat major depressive disorder, anxiety disorders, chronic pain conditions, and to help manage addictions. Common side-effects of antidepressants include dry mouth, weight gain, dizziness, hea ...

and

anticonvulsant Anticonvulsants (also known as antiepileptic drugs or recently as antiseizure drugs) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of b ...

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 dopa ...

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 and ...

. 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 List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

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 A prodrug is a medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be used to improve how the drug ...

amphetamine Amphetamine (contracted from alpha- methylphenethylamine) is a strong central nervous system (CNS) stimulant that is used in the treatment of attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity. It is also commonly used ...

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 repre ...

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 i ...

. 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