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 dopamine not absorbed by the postsynaptic neuron is blocked from re-entering the presynaptic neuron. This results in increased extracellular concentrations of dopamine and increase in dopaminergic neurotransmission.
The dopamine transporter is a membrane-spanning protein coded for in humans by the SLC6A3 gene, that pumps the neurotransmitter dopamine out of the synaptic cleft back into cytosol. In the cytosol, other transporters sequester the dopamine into vesicles for storage and later release. Dopamine reuptake via DAT provides the primary mechanism through which dopamine is cleared from synapses, although there may be an exception in the prefrontal cortex, where evidence points to a possibly larger role of the norepinephrine transporter.
Tetrabenazine is a drug for the symptomatic treatment of hyperkinetic movement disorders. It is sold under the brand names Nitoman and Xenazine among others. On August 15, 2008, the U.S. Food and Drug Administration approved the use of tetrabenazine to treat chorea associated with Huntington's disease. Although other drugs had been used "off label," tetrabenazine was the first approved treatment for Huntington's disease in the U.S. The compound has been known since the 1950s.
Dopaminergic means "related to dopamine", a common neurotransmitter. Dopaminergic substances or actions increase dopamine-related activity in the brain.
A monoamine releasing agent (MRA), or simply monoamine releaser, is a drug that induces the release of a monoamine neurotransmitter from the presynaptic neuron into the synapse, leading to an increase in the extracellular concentrations of the neurotransmitter. Many drugs induce their effects in the body and/or brain via the release of monoamine neurotransmitters, e.g., trace amines, many substituted amphetamines, and related compounds.
A monoamine reuptake inhibitor (MRI) is a drug that acts as a reuptake inhibitor of one or more of the three major monoamine neurotransmitters serotonin, norepinephrine, and dopamine by blocking the action of one or more of the respective monoamine transporters (MATs), which include the serotonin transporter (SERT), norepinephrine transporter (NET), and dopamine transporter (DAT). This in turn results in an increase in the synaptic concentrations of one or more of these neurotransmitters and therefore an increase in monoaminergic neurotransmission.
Flmodafinil, also known as bisfluoromodafinil and lauflumide, is a wakefulness-promoting agent related to modafinil which has been developed for treatment of a variety of different medical conditions. These include chronic fatigue syndrome, idiopathic hypersomnia, narcolepsy, attention deficit hyperactivity disorder (ADHD), and Alzheimer's disease. Aside its development as a potential pharmaceutical drug, flmodafinil is sold online and used non-medically as a nootropic.
CE-123, or as the active enantiomer (S)-CE-123, is an analog of modafinil, the most researched of a series of structurally related heterocyclic derivatives. In animal studies, CE-123 was found to improve performance on tests of learning and memory in a manner consistent with a nootropic effect profile. (S)-CE-123 has pro-motivational effects in animals, reverses tetrabenazine-induced motivational deficits, and could be useful in the treatment of motivational disorders in humans.
Esmodafinil (also known as (S)-modafinil or (+)-modafinil; developmental code name CRL-40983) is the enantiopure (S)-(+)-enantiomer of modafinil. Unlike armodafinil ((R)-(–)-modafinil), esmodafinil has never been marketed on its own.
Disorders of diminished motivation (DDM) are a group of disorders involving diminished motivation and associated emotions. Many different terms have been used to refer to diminished motivation. Often however, a spectrum is defined encompassing apathy, abulia, and akinetic mutism, with apathy the least severe and akinetic mutism the most extreme.
PRX-14040 is a selective dopamine reuptake inhibitor that was developed by Prexa Pharmaceuticals. It has 28-fold selectivity for the dopamine transporter over the norepinephrine transporter. Similarly to various other dopamine reuptake inhibitors, the drug has been found to reverse motivational deficits induced by the dopamine depleting agent tetrabenazine in animals.
RDS03-94, or RDS3-094, is an atypical dopamine reuptake inhibitor that was derived from the wakefulness-promoting agent modafinil.
JJC8-088 is a dopamine reuptake inhibitor (DRI) that was derived from the wakefulness-promoting agent modafinil.
A pro-motivational agent is a drug which increases motivation. They can be used in the treatment of motivational deficits, for instance in depression, schizophrenia, and attention deficit hyperactivity disorder (ADHD), as well as in the treatment of disorders of diminished motivation (DDMs), including apathy, abulia, and akinetic mutism, for instance due to stroke, traumatic brain injury, or neurodegenerative diseases. They are also used non-medically by healthy people to increase motivation and productivity, for instance in educational contexts.
CT-005404, or CT-5404, is an atypical dopamine reuptake inhibitor (DRI) that was derived from modafinil. It shows pro-motivational effects in animals and reverses motivational deficits induced by tetrabenazine and interleukin-1β. CT-005404 is described as being orally active in animals and having a long duration of action. It is under development by Chronos Therapeutics for treatment of motivational disorders. The drug was first described by 2018.
CE-158 is an atypical dopamine reuptake inhibitor (DRI) that was derived from modafinil. It is often but not always referred to as the enantiopure enantiomer (S,S)-CE-158 instead.
JJC8-016 is an atypical dopamine reuptake inhibitor (DRI) that was derived from modafinil. It was an early lead in the development of novel modafinil analogues with improved properties for potential use in the treatment of psychostimulant use disorder (PSUD).
JJC8-091 is an atypical dopamine reuptake inhibitor (DRI) that was derived from modafinil. It is a lead compound for potential treatment of psychostimulant use disorder (PSUD) and is under development by Encepheal Therapeutics for use as a pharmaceutical drug.
JJC8-089 is a dopamine reuptake inhibitor (DRI) that was derived from modafinil and is related to JJC8-016, JJC8-088, and JJC8-091. Its affinity (Ki) for the dopamine transporter (DAT) is 37.8 nM, for the norepinephrine transporter (NET) is 11,820 nM, for the serotonin transporter (SERT) is 6,800 nM, and for the sigma σ1 receptor is 2.24 nM. It also has significant affinity for several dopamine receptors. JJC8-089 has substantially higher affinity for the DAT than modafinil. The drug shows pro-motivational effects in animals. It was first described in the scientific literature by 2016.
