
Dopaminergic means "related to
dopamine
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. It is an amine synthesized ...
" (literally, "working on dopamine"), a common
neurotransmitter
A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a Chemical synapse, synapse. The cell receiving the signal, or target cell, may be another neuron, but could also be a gland or muscle cell.
Neurotra ...
.
Dopaminergic substances or actions increase dopamine-related activity in the brain.
Dopaminergic brain pathways facilitate dopamine-related activity. For example, certain
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
s such as the
dopamine transporter
The dopamine transporter (DAT, also sodium-dependent dopamine transporter) is a membrane-spanning protein coded for in humans by the ''SLC6A3'' gene (also known as ''DAT1''), that pumps the neurotransmitter dopamine out of the synaptic cleft ba ...
(DAT),
vesicular monoamine transporter 2
The solute carrier family 18 member 2 (SLC18A2) also known as vesicular monoamine transporter 2 (VMAT2) is a protein that in humans is encoded by the ''SLC18A2'' gene. VMAT2 is an integral membrane protein that transports monoamines—particul ...
(VMAT
2), and
dopamine receptors can be classified as dopaminergic, and
neuron
A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...
s that
synthesize or contain dopamine and
synapse
In the nervous system, a synapse is a structure that allows a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or a target effector cell. Synapses can be classified as either chemical or electrical, depending o ...
s with dopamine receptors in them may also be labeled as ''dopaminergic''.
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
s that regulate the
biosynthesis
Biosynthesis, i.e., chemical synthesis occurring in biological contexts, is a term most often referring to multi-step, enzyme-Catalysis, catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthe ...
or
metabolism
Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the co ...
of dopamine such as
aromatic L-amino acid decarboxylase
Aromatic L-amino acid decarboxylase (AADC or AAAD), also known as DOPA decarboxylase (DDC), tryptophan decarboxylase, and 5-hydroxytryptophan decarboxylase, is a lyase enzyme (), located in region 7p12.2-p12.1.
Mechanism
The enzyme uses pyri ...
or
DOPA decarboxylase
Aromatic L-amino acid decarboxylase (AADC or AAAD), also known as DOPA decarboxylase (DDC), tryptophan decarboxylase, and 5-hydroxytryptophan decarboxylase, is a lyase enzyme (), located in region 7p12.2-p12.1.
Mechanism
The enzyme uses pyri ...
,
monoamine oxidase
Monoamine oxidases (MAO) () are a family of enzymes that catalyze the oxidation of monoamines, employing oxygen to clip off their amine group. They are found bound to the outer membrane of mitochondria in most cell types of the body. The fi ...
(MAO), and
catechol ''O''-methyl transferase (COMT) may be referred to as ''dopaminergic'' as well.
Also, any
endogenous
Endogeny, in biology, refers to the property of originating or developing from within an organism, tissue, or cell.
For example, ''endogenous substances'', and ''endogenous processes'' are those that originate within a living system (e.g. an ...
or
exogenous
In a variety of contexts, exogeny or exogeneity () is the fact of an action or object originating externally. It is the opposite of endogeneity or endogeny, the fact of being influenced from within a system.
Economics
In an economic model, an ...
chemical substance
A chemical substance is a unique form of matter with constant chemical composition and characteristic properties. Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be com ...
that acts to affect dopamine receptors or dopamine release through indirect actions (for example, on neurons that synapse onto neurons that release dopamine or express dopamine receptors) can also be said to have ''dopaminergic'' effects, two prominent examples being
opioid
Opioids are a class of Drug, drugs that derive from, or mimic, natural substances found in the Papaver somniferum, opium poppy plant. Opioids work on opioid receptors in the brain and other organs to produce a variety of morphine-like effects, ...
s, which enhance dopamine release indirectly in the
reward pathway
The mesolimbic pathway, sometimes referred to as the reward pathway, is a dopaminergic pathway in the brain. The pathway connects the ventral tegmental area in the midbrain to the ventral striatum of the basal ganglia in the forebrain. The ventral ...
s, and some
substituted amphetamine
Substituted amphetamines, or simply amphetamines, are a chemical class, class of compounds based upon the amphetamine structure; it includes all derivative (chemistry), derivative compounds which are formed by replacing, or substitution reacti ...
s, which enhance dopamine release directly by binding to and inhibiting
VMAT2.
Dopaminergic agents
Dopamine precursors
Dopamine
precursors including
L-phenylalanine
Phenylalanine (symbol Phe or F) is an essential α-amino acid with the formula . It can be viewed as a benzyl group substituted for the methyl group of alanine, or a phenyl group in place of a terminal hydrogen of alanine. This essential amin ...
and
L-tyrosine
-Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a conditionally essential amino acid with a polar side group. The word "tyrosine" is ...
are used as
dietary supplement
A dietary supplement is a manufactured product intended to supplement a person's diet by taking a pill (pharmacy), pill, capsule (pharmacy), capsule, tablet (pharmacy), tablet, powder, or liquid. A supplement can provide nutrients eithe ...
s.
L-DOPA
-DOPA, also known as -3,4-dihydroxyphenylalanine and used medically as levodopa, is made and used as part of the normal biology of some plants and animals, including humans. Humans, as well as a portion of the other animals that utilize -DO ...
(Levodopa), another precursor, is used in the treatment of
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...
.
Prodrug
A prodrug is a pharmacologically inactive 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 ...
s of levodopa, including
melevodopa,
etilevodopa,
foslevodopa, and
XP-21279 also exist. They are inactive themselves but are converted into dopamine and hence act as non-selective dopamine receptor agonists.
Dopamine receptor ligands
Dopamine receptor agonists
Dopamine receptor agonists can be divided into
non-selective dopamine receptor agonists,
D1-like receptor agonists, and
D2-like receptor agonists.
Non-selective dopamine receptor agonists include
dopamine
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. It is an amine synthesized ...
,
deoxyepinephrine (epinine),
dinoxyline, and
dopexamine. They are mostly
peripherally selective drug Peripherally selective drugs have their primary mechanism of action outside of the central nervous system (CNS), usually because they are excluded from the CNS by the blood–brain barrier. By being excluded from the CNS, drugs may act on the rest o ...
s, are often also
adrenergic receptor agonist
An adrenergic agonist is a drug that stimulates a response from the adrenergic receptors. The five main categories of adrenergic receptors are: α1, α2, β1, β2, and β3, although there are more subtypes, and agonists vary in specificity between ...
s, and are used to treat certain
cardiovascular conditions.
D
2-like receptor agonists include the
ergoline
Ergoline is a core structure in many alkaloids and their synthetic derivatives. Ergoline alkaloids were first characterized in ergot. Some of these are implicated in the condition of ergotism, which can take a convulsive form or a gangrenous for ...
s
bromocriptine
Bromocriptine, originally marketed as Parlodel and subsequently under many brand names, is an ergoline derivative and dopamine agonist that is used in the treatment of pituitary tumors, Parkinson's disease, hyperprolactinaemia, neuroleptic malig ...
,
cabergoline
Cabergoline, sold under the brand name Dostinex among others, is a dopaminergic medication used in the treatment of high prolactin levels, prolactinomas, Parkinson's disease, and for other indications. It is taken by mouth.
Cabergoline is an ...
,
dihydroergocryptine,
ergoloid,
lisuride,
metergoline,
pergolide,
quinagolide
Quinagolide (, ), sold under the brand name Norprolac, is a binding selectivity, selective dopamine receptor, dopamine D2 receptor, D2 receptor agonist which is used to manage hyperprolactinemia. It has also been found to be effective in the trea ...
, and
terguride; the
morphine
Morphine, formerly also called morphia, is an opiate that is found naturally in opium, a dark brown resin produced by drying the latex of opium poppies (''Papaver somniferum''). It is mainly used as an analgesic (pain medication). There are ...
analogue
apomorphine; and the structurally distinct agents
piribedil,
pramipexole,
ropinirole,
rotigotine, and
talipexole. Some of these agents also have weak affinity for the D
1-like receptors. They are used to treat
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...
,
restless legs syndrome
Restless legs syndrome (RLS), also known as Willis–Ekbom disease (WED), is a neurological disorder, usually chronic, that causes an overwhelming urge to move one's legs. There is often an unpleasant feeling in the legs that improves temporaril ...
,
hyperprolactinemia
Hyperprolactinaemia (also spelled hyperprolactinemia) is a condition characterized by abnormally high levels of prolactin in the blood. In women, normal prolactin levels average to about 13 ng/mL, while in men, they average 5 ng/mL. ...
,
prolactinoma
A prolactinoma is a tumor (adenoma) of the pituitary gland that produces the hormone prolactin. It is the most common type of functioning pituitary tumor. Symptoms of prolactinoma are due to abnormally high levels of prolactin in the blood ( hyp ...
s,
acromegaly
Acromegaly is a disorder that results in excess growth of certain parts of the human body. It is caused by excess growth hormone (GH) after the growth plates have closed. The initial symptom is typically enlargement of the hands and feet. There ...
,
erectile dysfunction
Erectile dysfunction (ED), also referred to as impotence, is a form of sexual dysfunction in males characterized by the persistent or recurring inability to achieve or maintain a Human penis, penile erection with sufficient rigidity and durat ...
, and for
lactation suppression. They are also being studied in the treatment of
depression and are sometimes used in the treatment of
disorders of diminished motivation
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 ...
like
apathy
Apathy, also referred to as indifference, 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 i ...
,
abulia
In neurology, abulia, or aboulia (from , meaning "will"),Bailly, A. (2000). Dictionnaire Grec Français, Éditions Hachette. refers to a lack of will or initiative and can be seen as a disorder of diminished motivation. Abulia falls in the midd ...
, and
akinetic mutism.
D
1-like receptor agonists include
6-Br-APB,
A-68930,
A-77636,
A-86929,
adrogolide,
dihydrexidine,
dinapsoline,
doxanthrine,
fenoldopam,
razpipadon,
SKF-81,297,
SKF-82,958,
SKF-89,145,
tavapadon, and
trepipam. They have been researched for and are under development for the treatment of
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...
and
dementia-related apathy. Peripherally selective D
1-like receptor agonists like fenoldopam are used to treat
hypertensive crisis
Severely elevated blood pressure (equal to or greater than 180 mmHg systolic or 120 mmHg diastolic) is referred to as a hypertensive crisis (sometimes termed malignant or accelerated hypertension), due to the high risk of complications. People ...
.
Dopamine receptor positive allosteric modulators
Positive allosteric modulator
In pharmacology and biochemistry, allosteric modulators are a group of substances that bind to a receptor to change that receptor's response to stimuli. Some of them, like benzodiazepines or alcohol, function as psychoactive drugs. The site that ...
s of the dopamine
D1 receptor like
mevidalen and
glovadalen are under development for the treatment of
Lewy body disease
Lewy body dementia (LBD) is an umbrella term for two similar and common subtypes of dementia: dementia with Lewy bodies (DLB) and
Parkinson's disease dementia (PDD). Both are characterized by changes in thinking, movement, behavior, and mood. The ...
and
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...
.
Dopamine receptor antagonists
Dopamine receptor antagonist
A dopamine antagonist, also known as an anti-dopaminergic and a dopamine receptor antagonist (DRA), is a type of drug which blocks dopamine receptors by receptor antagonism. Most antipsychotics are dopamine antagonists, and have been used in tr ...
s including
typical antipsychotic
Typical antipsychotics (also known as major tranquilizers, and first generation antipsychotics) are a class of antipsychotic drugs first developed in the 1950s and used to treat psychosis (in particular, schizophrenia). Typical antipsychotics m ...
s such as
chlorpromazine
Chlorpromazine (CPZ), marketed under the brand names Thorazine and Largactil among others, is an antipsychotic medication. It is primarily used to treat psychotic disorders such as schizophrenia. Other uses include the treatment of bipolar d ...
(Thorazine),
fluphenazine,
haloperidol
Haloperidol, sold under the brand name Haldol among others, is a typical antipsychotic medication. Haloperidol is used in the treatment of schizophrenia, tics in Tourette syndrome, mania in bipolar disorder, delirium, agitation, acute psychos ...
(Haldol),
loxapine,
molindone,
perphenazine,
pimozide
Pimozide (sold under the brand name Orap) is a neuroleptic medication, drug of the diphenylbutylpiperidine class. It was discovered at Janssen Pharmaceutica in 1963. It has a high potency compared to chlorpromazine (ratio 50-70:1). On a weigh ...
,
thioridazine
Thioridazine (Mellaril or Melleril) is a first generation antipsychotic drug belonging to the phenothiazine drug group and was previously widely used in the treatment of schizophrenia and psychosis. The branded product was withdrawn worldwid ...
,
thiothixene
Tiotixene, or thiothixene is a typical antipsychotic agent currently sold under the brand name Navane which is predominantly utilised to treat acute and chronic schizophrenia. Beyond its primary Indication (medicine), indication, it can exhibit ...
, and
trifluoperazine, the
atypical antipsychotic
The atypical antipsychotics (AAP), also known as second generation antipsychotics (SGAs) and serotonin–dopamine antagonists (SDAs), are a group of antipsychotic drugs (antipsychotic drugs in general are also known as tranquilizers and neurol ...
s such as
amisulpride
Amisulpride, sold under the brand names Socian and Barhemsys, is a medication used in the treatment of schizophrenia, acute psychotic episodes, depression, and nausea and vomiting. It is specifically used at lower doses intravenously to prev ...
,
clozapine
Clozapine, sold under the brand name Clozaril among others, is a psychiatric medication and was the first atypical antipsychotic to be discovered. It is used primarily to treat people with schizophrenia and schizoaffective disorder who have ...
,
olanzapine
Olanzapine, sold under the brand name Zyprexa among others, is an atypical antipsychotic primarily used to treat schizophrenia and bipolar disorder. It is also sometimes used off-label for treatment of chemotherapy-induced nausea and vomitin ...
,
quetiapine
Quetiapine ( ), sold under the brand name Seroquel among others, is an atypical antipsychotic medication used in the treatment of schizophrenia, bipolar disorder, bipolar depression, and major depressive disorder. Despite being widely prescri ...
(Seroquel),
risperidone
Risperidone, sold under the brand name Risperdal among others, is an atypical antipsychotic used to treat schizophrenia and bipolar disorder, as well as aggressive and self-injurious behaviors associated with autism spectrum disorder. It is t ...
(Risperdal),
sulpiride
Sulpiride, sold under the brand name Dogmatil among others, is an atypical antipsychotic (although some texts have referred to it as a typical antipsychotic) medication of the benzamide class which is used mainly in the treatment of psychosi ...
, and
ziprasidone, and
antiemetic
An antiemetic is a drug that is effective against vomiting and nausea. Antiemetics are typically used to treat motion sickness and the side effects of opioid analgesics, general anaesthetics, and chemotherapy directed against cancer. They may ...
s like
domperidone
Domperidone, sold under the brand name Motilium among others, is a dopamine antagonist medication which is used to treat nausea and vomiting and certain gastrointestinal problems like gastroparesis (delayed gastric emptying). It raises the ...
,
metoclopramide
Metoclopramide is a medication used to treat nausea, vomiting, gastroparesis, and gastroesophageal reflux disease. It is also used to treat migraine headaches.
Common side effects include feeling tired, diarrhea, akathisia, and tardive dyski ...
, and
prochlorperazine, among others, which are used in the treatment of
schizophrenia
Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, f ...
and
bipolar disorder
Bipolar disorder (BD), previously known as manic depression, is a mental disorder characterized by periods of Depression (mood), depression and periods of abnormally elevated Mood (psychology), mood that each last from days to weeks, and in ...
as
antipsychotic
Antipsychotics, previously known as neuroleptics and major tranquilizers, are a class of Psychiatric medication, psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), p ...
s, and
nausea
Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat.
Over 30 d ...
and
vomiting
Vomiting (also known as emesis, puking and throwing up) is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose.
Vomiting can be the result of ailments like food poisoning, gastroenteritis, pre ...
.
Dopamine receptor antagonists can be divided into
D1-like receptor antagonists and
D2-like receptor antagonists.
Ecopipam is an example of a D
1-like receptor antagonist.
At low doses, dopamine
D2 and
D3 receptor antagonists can preferentially block
presynaptic
In the nervous system, a synapse is a structure that allows a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or a target effector cell. Synapses can be classified as either chemical or electrical, depending o ...
dopamine D
2 and D
3 autoreceptor
An autoreceptor is a type of Receptor (biochemistry), receptor located in the cell membrane, membranes of neuron, nerve cells. It serves as part of a negative feedback loop in signal transduction. It is only sensitive to the neurotransmitters or ...
s and thereby increase dopamine levels and enhance dopaminergic neurotransmission.
Examples of dopamine D
2 and D
3 receptor antagonists which have been used in this way include
amisulpride
Amisulpride, sold under the brand names Socian and Barhemsys, is a medication used in the treatment of schizophrenia, acute psychotic episodes, depression, and nausea and vomiting. It is specifically used at lower doses intravenously to prev ...
,
sulpiride
Sulpiride, sold under the brand name Dogmatil among others, is an atypical antipsychotic (although some texts have referred to it as a typical antipsychotic) medication of the benzamide class which is used mainly in the treatment of psychosi ...
,
and
ENX-104.
Dopamine receptor negative allosteric modulators
Negative allosteric modulator
In pharmacology and biochemistry, allosteric modulators are a group of substances that bind to a receptor to change that receptor's response to stimuli. Some of them, like benzodiazepines or alcohol, function as psychoactive drugs. The site that a ...
s of the dopamine receptors, such as
SB269652, have been identified and are being researched.
Dopamine transporter modulators and related
Dopamine reuptake inhibitors
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 ...
s (DRIs) or
dopamine transporter
The dopamine transporter (DAT, also sodium-dependent dopamine transporter) is a membrane-spanning protein coded for in humans by the ''SLC6A3'' gene (also known as ''DAT1''), that pumps the neurotransmitter dopamine out of the synaptic cleft ba ...
(DAT) inhibitors such as
methylphenidate
Methylphenidate, sold under the brand names Ritalin ( ) and Concerta ( ) among others, is a central nervous system (CNS) stimulant used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. It may be taken Oral adm ...
(Ritalin),
amineptine
Amineptine, formerly sold under the brand name Survector among others, is an atypical antidepressant of the tricyclic antidepressant (TCA) family. It acts as a selective and mixed dopamine reuptake inhibitor and releasing agent, and to a le ...
,
nomifensine,
cocaine
Cocaine is a tropane alkaloid and central nervous system stimulant, derived primarily from the leaves of two South American coca plants, ''Erythroxylum coca'' and ''Erythroxylum novogranatense, E. novogranatense'', which are cultivated a ...
,
bupropion
Bupropion, formerly called amfebutamone, and sold under the brand name Wellbutrin among others, is an atypical antidepressant that is indicated in the treatment of major depressive disorder, seasonal affective disorder, and to support smo ...
,
modafinil
Modafinil, sold under the brand name Provigil among others, is a central nervous system (CNS) stimulant and wakefulness-promoting agent, eugeroic (wakefulness promoter) medication used primarily to treat narcolepsy, a sleep disorder characteri ...
,
armodafinil
Armodafinil, sold under the brand name Nuvigil, is a wakefulness-promoting medication which is used to treat excessive daytime sleepiness associated with obstructive sleep apnea, narcolepsy, and shift work disorder. It is also used off-label ...
,
phenylpiracetam
Phenylpiracetam, also known as fonturacetam () and sold under the brand names Phenotropil, Actitropil, and Carphedon among others, is a psychostimulant, stimulant and nootropic medication used in Russia and certain other Eastern European countr ...
,
mesocarb, and
vanoxerine, among others. They are used in the treatment of
attention-deficit hyperactivity disorder
Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by symptoms of inattention, hyperactivity, impulsivity, and emotional dysregulation that are excessive and pervasive, impairing in multiple con ...
(ADHD) as
psychostimulant
Stimulants (also known as central nervous system stimulants, or psychostimulants, or colloquially as uppers) are a class of drugs that increase alertness. They are used for various purposes, such as enhancing attention, motivation, cognition ...
s,
narcolepsy
Narcolepsy is a chronic neurological disorder that impairs the ability to regulate sleep–wake cycles, and specifically impacts REM (rapid eye movement) sleep. The symptoms of narcolepsy include excessive daytime sleepiness (EDS), sleep-r ...
as
wakefulness-promoting agent
A wakefulness-promoting agent (WPA), or wake-promoting agent, is a drug that increases wakefulness and arousal. They are similar to but distinct from psychostimulants, which not only promote wakefulness but also produce other more overt central ...
s,
obesity
Obesity is a medical condition, considered by multiple organizations to be a disease, in which excess Adipose tissue, body fat has accumulated to such an extent that it can potentially have negative effects on health. People are classifi ...
and
binge eating disorder
Binge eating disorder (BED) is an eating disorder characterized by frequent and recurrent binge eating episodes with associated negative psychological and social problems, but without the compensatory behaviors common to bulimia nervosa, OSFE ...
as
appetite suppressant
An anorectic is a drug that reduces appetite, resulting in lower food consumption, leading to weight loss. These substances work by affecting the central nervous system or certain neurotransmitters to create a feeling of fullness or reduce the desi ...
s,
depression as
antidepressant
Antidepressants are a class of medications used to treat major depressive disorder, anxiety disorders, chronic pain, and addiction.
Common side effects of antidepressants include Xerostomia, dry mouth, weight gain, dizziness, headaches, akathi ...
s, and
fatigue
Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself.
Fatigue (in the medical sense) is sometimes associated wit ...
as
pro-motivational agents. They are also used as
illicit street
A street is a public thoroughfare in a city, town or village, typically lined with Building, buildings on one or both sides. Streets often include pavements (sidewalks), pedestrian crossings, and sometimes amenities like Street light, streetligh ...
and
recreational drug
Recreational drug use is the use of one or more psychoactive drugs to induce an altered state of consciousness, either for pleasure or for some other casual purpose or pastime. When a psychoactive drug enters the user's body, it induces an Sub ...
s due to their potentially
euphoriant and psychostimulant effects.
Dopamine releasing agents
Dopamine releasing agents (DRAs) such as
phenethylamine
Phenethylamine (PEA) is an organic compound, natural monoamine alkaloid, and trace amine, which acts as a central nervous system stimulant in humans. In the brain, phenethylamine regulates monoamine neurotransmission by binding to trace ami ...
,
amphetamine
Amphetamine (contracted from Alpha and beta carbon, alpha-methylphenethylamine, methylphenethylamine) is a central nervous system (CNS) stimulant that is used in the treatment of attention deficit hyperactivity disorder (ADHD), narcolepsy, an ...
,
lisdexamfetamine
Lisdexamfetamine, sold under the brand names Vyvanse and Elvanse among others, is a stimulant medication that is used as a treatment for attention deficit hyperactivity disorder (ADHD) in children and adults and for moderate-to-severe binge ...
(Vyvanse),
methamphetamine
Methamphetamine (contracted from ) is a potent central nervous system (CNS) stimulant that is mainly used as a recreational drug use, recreational or Performance-enhancing substance, performance-enhancing drug and less commonly as a secon ...
,
methylenedioxymethamphetamine
3,4-Methylenedioxymethamphetamine (MDMA), commonly known as ecstasy (tablet form), and molly (crystal form), is an empathogen–entactogenic drug with stimulant and minor psychedelic properties. In studies, it has been used alongside psych ...
(MDMA),
phenmetrazine
Phenmetrazine, sold under the brand name Preludin among others, is a stimulant drug first chemical synthesis, synthesized in 1952 and originally used as an appetite suppressant, but withdrawn drug, withdrawn from the market in the 1980s due to ...
,
pemoline
Pemoline, formerly sold under the brand name Cylert among others, is a stimulant medication which was used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy,- it has since been discontinued in most countries due ...
,
4-methylaminorex
4-Methylaminorex (4-MAR, 4-MAX) is a stimulant drug of the 2-amino-5-aryloxazoline group that was first synthesized in 1960 by McNeil Laboratories. It is also known by its street name "U4Euh" ("Euphoria"). It is banned in many countries as a sti ...
(4-MAR),
phentermine
Phentermine, sold under the brand name Adipex-P among others, is a medication used together with diet and exercise to treat obesity. It is available by itself or as the combination phentermine/topiramate. Phentermine is taken by mouth.
Com ...
, and
benzylpiperazine, among many others, which, like DRIs, are used in the treatment of
attention-deficit hyperactivity disorder
Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by symptoms of inattention, hyperactivity, impulsivity, and emotional dysregulation that are excessive and pervasive, impairing in multiple con ...
(ADHD) and
narcolepsy
Narcolepsy is a chronic neurological disorder that impairs the ability to regulate sleep–wake cycles, and specifically impacts REM (rapid eye movement) sleep. The symptoms of narcolepsy include excessive daytime sleepiness (EDS), sleep-r ...
as
psychostimulant
Stimulants (also known as central nervous system stimulants, or psychostimulants, or colloquially as uppers) are a class of drugs that increase alertness. They are used for various purposes, such as enhancing attention, motivation, cognition ...
s,
obesity
Obesity is a medical condition, considered by multiple organizations to be a disease, in which excess Adipose tissue, body fat has accumulated to such an extent that it can potentially have negative effects on health. People are classifi ...
as
anorectic
An anorectic is a drug that reduces appetite, resulting in lower food consumption, leading to weight loss. These substances work by affecting the central nervous system or certain neurotransmitters to create a feeling of fullness or reduce the desi ...
s,
depression and
anxiety
Anxiety is an emotion characterised by an unpleasant state of inner wikt:turmoil, turmoil and includes feelings of dread over Anticipation, anticipated events. Anxiety is different from fear in that fear is defined as the emotional response ...
as
antidepressant
Antidepressants are a class of medications used to treat major depressive disorder, anxiety disorders, chronic pain, and addiction.
Common side effects of antidepressants include Xerostomia, dry mouth, weight gain, dizziness, headaches, akathi ...
s and
anxiolytic
An anxiolytic (; also antipanic or anti-anxiety agent) is a medication or other intervention that reduces anxiety. This effect is in contrast to anxiogenic agents which increase anxiety. Anxiolytic medications are used for the treatment of anxie ...
s respectively,
drug addiction
Addiction is a neuropsychological disorder characterized by a persistent and intense urge to use a drug or engage in a behavior that produces natural reward, despite substantial harm and other negative consequences. Repetitive drug use can ...
as
anticraving agents, and
sexual dysfunction
Sexual dysfunction is difficulty experienced by an individual or partners during any stage of normal sexual activity, including physical pleasure, desire, preference, arousal, or orgasm. The World Health Organization defines sexual dysfunction ...
as
aphrodisiac
An aphrodisiac is a substance that increases libido, sexual desire, sexual attraction, sexual pleasure, or sexual behavior. These substances range from a variety of plants, spices, and foods to synthetic chemicals. Natural aphrodisiacs, such as ...
s. Many of these compounds are also
illicit street
A street is a public thoroughfare in a city, town or village, typically lined with Building, buildings on one or both sides. Streets often include pavements (sidewalks), pedestrian crossings, and sometimes amenities like Street light, streetligh ...
or
recreational drug
Recreational drug use is the use of one or more psychoactive drugs to induce an altered state of consciousness, either for pleasure or for some other casual purpose or pastime. When a psychoactive drug enters the user's body, it induces an Sub ...
s.
Dopaminergic activity enhancers
Dopaminergic activity enhancers such as the
prescription drug
A prescription drug (also prescription medication, prescription medicine or prescription-only medication) is a pharmaceutical drug that is permitted to be dispensed only to those with a medical prescription. In contrast, over-the-counter drugs c ...
selegiline
Selegiline, also known as L-deprenyl and sold under the brand names Eldepryl, Zelapar, and Emsam among others, is a medication which is used in the treatment of Parkinson's disease and major depressive disorder. It has also been studied and us ...
(deprenyl) and the
research chemical
Research chemicals are chemical substances which scientists use for medical and scientific research purposes. One characteristic of a research chemical is that it is for laboratory research use only; a research chemical is not intended for human ...
s
BPAP and
PPAP enhance the
action potential
An action potential (also known as a nerve impulse or "spike" when in a neuron) is a series of quick changes in voltage across a cell membrane. An action potential occurs when the membrane potential of a specific Cell (biology), cell rapidly ri ...
-mediated release of dopamine.
This is in contrast to dopamine releasing agents like amphetamine, which induce the uncontrolled release of dopamine regardless of electrical stimulation.
The effects of the activity enhancers may be mediated by
intracellular
This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions ...
TAAR1
Trace amine-associated receptor 1 (TAAR1) is a trace amine-associated receptor (TAAR) protein that in humans is encoded by the ''TAAR1'' gene.
TAAR1 is a primarily intracellular amine-activated and G protein-coupled receptor (GPCR) that is p ...
agonism
Agonism (from Greek 'struggle') is a political and social theory that emphasizes the potentially positive aspects of certain forms of conflict. It accepts a permanent place for such conflict in the political sphere, but seeks to show how indivi ...
coupled with uptake into monoaminergic neurons by
monoamine transporter
Monoamine transporters (MATs) are proteins that function as integral Cell membrane, plasma-membrane Neurotransmitter transporter, transporters to regulate concentrations of extracellular monoamine neurotransmitters. The three major classes are se ...
s.
Dopaminergic activity enhancers are of interest in the potential treatment of a number of
medical disorder
A disease is a particular abnormal condition that adversely affects the structure or function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical conditions that are asso ...
s, such as
depression and
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...
. To date, only
phenylethylamine,
tryptamine
Tryptamine is an indolamine metabolite of the essential amino acid tryptophan. The chemical structure is defined by an indole—a fused benzene and pyrrole ring, and a 2-aminoethyl group at the second carbon (third aromatic atom, with the firs ...
, and
tyramine
Tyramine ( ) (also spelled tyramin), also known under several other names, is a naturally occurring trace amine derived from the amino acid tyrosine. Tyramine acts as a catecholamine releasing agent. Notably, it is unable to cross the bl ...
have been identified as endogenous activity enhancers.
Dopamine depleting agents
Vesicular monoamine transporter 2
The solute carrier family 18 member 2 (SLC18A2) also known as vesicular monoamine transporter 2 (VMAT2) is a protein that in humans is encoded by the ''SLC18A2'' gene. VMAT2 is an integral membrane protein that transports monoamines—particul ...
(VMAT
2) inhibitors such as
reserpine
Reserpine is a drug that is used for the treatment of hypertension, high blood pressure, usually in combination with a thiazide diuretic or vasodilator. Large clinical trials have shown that combined treatment with reserpine plus a thiazide diur ...
,
tetrabenazine,
valbenazine, and
deutetrabenazine act as
dopamine depleting agents and are used as
sympatholytics or
antihypertensive
Antihypertensives are a class of drugs that are used to treat hypertension (high blood pressure). Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke, heart failure, kidney failure and myocardial infa ...
s, to treat
tardive dyskinesia
Tardive dyskinesia (TD) is an iatrogenic disorder that results in involuntary repetitive body movements, which may include grimacing, sticking out the tongue or smacking the lips, which occurs following treatment with medication. Additional mo ...
, and in the past as
antipsychotic
Antipsychotics, previously known as neuroleptics and major tranquilizers, are a class of Psychiatric medication, psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), p ...
s. They have been associated with side effects including
depression,
apathy
Apathy, also referred to as indifference, 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 i ...
,
fatigue
Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself.
Fatigue (in the medical sense) is sometimes associated wit ...
,
amotivation
Amotivational syndrome is a chronic psychiatric disorder characterized by signs that are linked to cognitive and emotional states such as detachment, blunted emotion and drives, executive functions like memory and attention, disinterest, passivi ...
, and
suicidality.
Dopamine metabolism modulators
Monoamine oxidase inhibitors
Monoamine oxidase
Monoamine oxidases (MAO) () are a family of enzymes that catalyze the oxidation of monoamines, employing oxygen to clip off their amine group. They are found bound to the outer membrane of mitochondria in most cell types of the body. The fi ...
(MAO)
inhibitor
Inhibitor or inhibition may refer to:
Biology
* Enzyme inhibitor, a substance that binds to an enzyme and decreases the enzyme's activity
* Reuptake inhibitor, a substance that increases neurotransmission by blocking the reuptake of a neurotransmi ...
s (MAOIs) including
non-selective agents such as
phenelzine
Phenelzine, sold under the brand name Nardil among others, is a non-selective and irreversible monoamine oxidase inhibitor (MAOI) of the hydrazine family which is primarily used as an antidepressant and anxiolytic to treat depression and a ...
,
tranylcypromine
Tranylcypromine, sold under the brand name Parnate among others, is a monoamine oxidase inhibitor (MAOI). More specifically, tranylcypromine acts as nonselective and irreversible inhibitor of the enzyme monoamine oxidase (MAO). It is used a ...
,
isocarboxazid, and
pargyline,
MAOA selective agents like
moclobemide
Moclobemide, sold under the brand names Amira, Aurorix, Clobemix, Depnil and Manerix among others, is a reversible inhibitor of monoamine oxidase A (RIMA) drug primarily used to treat Clinical depression, depression and social anxiety. It is not ...
and
clorgyline, and
MAOB selective agents such as
selegiline
Selegiline, also known as L-deprenyl and sold under the brand names Eldepryl, Zelapar, and Emsam among others, is a medication which is used in the treatment of Parkinson's disease and major depressive disorder. It has also been studied and us ...
and
rasagiline
Rasagiline, sold under the brand name Azilect among others, is a medication which is used in the treatment of Parkinson's disease. It is used as a monotherapy to treat symptoms in early Parkinson's disease or as an adjunct therapy in more advan ...
, as well as the
harmala alkaloid
Harmala alkaloids are several alkaloids that act as monoamine oxidase inhibitors (MAOIs). These alkaloids are found in the seeds of ''Peganum harmala'' (also known as harmal or Syrian rue), as well as ''Banisteriopsis caapi'' (ayahuasca), leave ...
s like
harmine,
harmaline,
tetrahydroharmine,
harmalol
Harmalol is a bioactive β-carboline and a member of the harmala alkaloid
Harmala alkaloids are several alkaloids that act as monoamine oxidase inhibitors (MAOIs). These alkaloids are found in the seeds of ''Peganum harmala'' (also known as ...
,
harman, and
norharman, which are found to varying degrees in ''
Nicotiana tabacum
''Nicotiana tabacum'', or cultivated tobacco, is an annually grown herbaceous plant of the genus ''Nicotiana''. ''N. tabacum'' is the most commonly grown species in the genus ''Nicotiana,'' as the plant's leaves are commercially harvested to be ...
'' (tobacco), ''
Banisteriopsis caapi
''Banisteriopsis caapi'', also known as, caapi, soul vine, yagé (yage), or ayahuasca (the latter of which also refers to the psychedelic decoction made with the vine and a plant source of dimethyltryptamine) is a South American liana of the fam ...
'' (ayahuasca, yage), ''
Peganum harmala
''Peganum harmala'', commonly called wild rue, Syrian rue, African rue, esfand or espand,Mahmoud OmidsalaEsfand: a common weed found in Persia, Central Asia, and the adjacent areasEncyclopædia Iranica Vol. VIII, Fasc. 6, pp. 583–584. Origina ...
'' (Harmal, Syrian Rue), ''
Passiflora incarnata
''Passiflora incarnata'', commonly known as maypop, purple passionflower, true passionflower, wild apricot, and wild passion vine, is a fast-growing Perennial plant, perennial vine with climbing or trailing stems. A member of the passionflower ge ...
'' (Passion Flower), and ''
Tribulus terrestris
''Tribulus terrestris'' is an annual plant in the caltrop family (Zygophyllaceae) widely distributed around the world. It is adapted to thrive in dry climate locations in which few other plants can survive.
It is native to warm temperate and t ...
'', among others, which are used in the treatment of
depression and
anxiety
Anxiety is an emotion characterised by an unpleasant state of inner wikt:turmoil, turmoil and includes feelings of dread over Anticipation, anticipated events. Anxiety is different from fear in that fear is defined as the emotional response ...
as
antidepressant
Antidepressants are a class of medications used to treat major depressive disorder, anxiety disorders, chronic pain, and addiction.
Common side effects of antidepressants include Xerostomia, dry mouth, weight gain, dizziness, headaches, akathi ...
s and
anxiolytic
An anxiolytic (; also antipanic or anti-anxiety agent) is a medication or other intervention that reduces anxiety. This effect is in contrast to anxiogenic agents which increase anxiety. Anxiolytic medications are used for the treatment of anxie ...
s, respectively, in the treatment of
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...
and
dementia
Dementia is a syndrome associated with many neurodegenerative diseases, characterized by a general decline in cognitive abilities that affects a person's ability to perform activities of daily living, everyday activities. This typically invo ...
, and for the
recreational purpose of boosting the effects of certain
drug
A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via insufflation (medicine), inhalation, drug i ...
s like
phenethylamine
Phenethylamine (PEA) is an organic compound, natural monoamine alkaloid, and trace amine, which acts as a central nervous system stimulant in humans. In the brain, phenethylamine regulates monoamine neurotransmission by binding to trace ami ...
(PEA) and
psychedelics like
dimethyltryptamine
Dimethyltryptamine (DMT), also known as ''N'',''N''-dimethyltryptamine (''N'',''N''-DMT), is a Psychedelic drug, serotonergic hallucinogen and Investigational New Drug, investigational drug of the substituted tryptamine, tryptamine family tha ...
(DMT) via inhibiting their
metabolism
Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the co ...
.
Catechol ''O''-methyltransferase inhibitors
Catechol ''O''-methyl transferase (COMT)
inhibitors such as
entacapone,
opicapone
Opicapone, sold under the brand name Ongentys, is a medication which is administered together with levodopa in people with Parkinson's disease. Opicapone is a Catechol-O-methyltransferase inhibitor, catechol-O-methyltransferase (COMT) inhibito ...
, and
tolcapone, which are used in the treatment of
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...
. Entacapone and opicapone are
peripherally selective, but tolcapone significantly crosses the
blood–brain barrier
The blood–brain barrier (BBB) is a highly selective semipermeable membrane, semipermeable border of endothelium, endothelial cells that regulates the transfer of solutes and chemicals between the circulatory system and the central nervous system ...
. Tolcapone is under study for potential treatment of certain
psychiatric disorder
A mental disorder, also referred to as a mental illness, a mental health condition, or a psychiatric disability, is a behavioral or mental pattern that causes significant distress or impairment of personal functioning. A mental disorder is ...
s such as
obsessive–compulsive disorder
Obsessive–compulsive disorder (OCD) is a mental disorder in which an individual has intrusive thoughts (an ''obsession'') and feels the need to perform certain routines (''Compulsive behavior, compulsions'') repeatedly to relieve the dis ...
and
schizophrenia
Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, f ...
.
Aromatic L-amino acid decarboxylase inhibitors
Aromatic L-amino acid decarboxylase
Aromatic L-amino acid decarboxylase (AADC or AAAD), also known as DOPA decarboxylase (DDC), tryptophan decarboxylase, and 5-hydroxytryptophan decarboxylase, is a lyase enzyme (), located in region 7p12.2-p12.1.
Mechanism
The enzyme uses pyri ...
(AAAD) or
DOPA decarboxylase inhibitors including
benserazide
Benserazide is a peripherally acting aromatic L-amino acid decarboxylase or DOPA decarboxylase inhibitor, which is unable to cross the blood–brain barrier.
It is on the World Health Organization's List of Essential Medicines.
Medical use ...
,
carbidopa
Carbidopa, sold under the brand name Lodosyn, is a medication given to people with Parkinson's disease in order to inhibit peripheral metabolism of levodopa. This property is significant in that it allows a greater proportion of administered levo ...
, and
methyldopa
Methyldopa, also known as α-methyl-L-DOPA and sold under the brand name Aldomet among others, is a medication used for high blood pressure. It is one of the preferred treatments for high blood pressure in pregnancy. For other types of high blo ...
, which are used in the treatment of
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...
in
augmentation of
L-DOPA
-DOPA, also known as -3,4-dihydroxyphenylalanine and used medically as levodopa, is made and used as part of the normal biology of some plants and animals, including humans. Humans, as well as a portion of the other animals that utilize -DO ...
to block the
peripheral
A peripheral device, or simply peripheral, is an auxiliary hardware device that a computer uses to transfer information externally. A peripheral is a hardware component that is accessible to and controlled by a computer but is not a core compo ...
conversion of
dopamine
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. It is an amine synthesized ...
, thereby inhibiting undesirable
side-effects
In medicine, a side effect is an effect of the use of a medicinal drug or other treatment, usually adverse but sometimes beneficial, that is unintended. Herbal and traditional medicines also have side effects.
A drug or procedure usually used ...
, and as
sympatholytic or
antihypertensive
Antihypertensives are a class of drugs that are used to treat hypertension (high blood pressure). Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke, heart failure, kidney failure and myocardial infa ...
agents.
Dopamine β-hydroxylase inhibitors
Dopamine β-hydroxylase
Dopamine beta-hydroxylase (DBH), also known as dopamine beta-monooxygenase, is an enzyme () that in humans is encoded by the DBH gene. Dopamine beta-hydroxylase catalysis, catalyzes the conversion of dopamine to norepinephrine.
The three substr ...
inhibitors like
disulfiram
Disulfiram is a medication used to support the treatment of chronic alcoholism by producing an acute sensitivity to ethanol (drinking alcohol). Disulfiram works by Enzyme inhibition, inhibiting the enzyme aldehyde dehydrogenase (specifically ALD ...
(Antabuse), which can be used in the treatment of addiction to cocaine and similar dopaminergic drugs as a deterrent drug. The excess dopamine resulting from inhibition of the dopamine β-hydroxylase enzyme increases unpleasant symptoms such as anxiety, higher blood pressure, and restlessness. Disulfiram is not an
anticraving agent, because it does not decrease craving for drugs. Instead,
positive punishment
Punishment is any change in a human or animal's surroundings which, occurring after a given behavior or response, reduces the likelihood of that behavior occurring again in the future. Reinforcement, referring to any behavior that increases the l ...
from its unpleasant effects deters drug consumption.
Other dopamine β-hydroxylase inhibitors include the centrally active
nepicastat and the
peripherally selective etamicastat and
zamicastat.
Other enzyme inhibitors
Phenylalanine hydroxylase
Phenylalanine hydroxylase (PAH) () is an enzyme that catalyzes the hydroxylation of the aromatic side-chain of phenylalanine to generate tyrosine. PAH is one of three members of the biopterin-dependent aromatic amino acid hydroxylases, a clas ...
inhibitors like
3,4-dihydroxystyrene), which is currently only a
research chemical
Research chemicals are chemical substances which scientists use for medical and scientific research purposes. One characteristic of a research chemical is that it is for laboratory research use only; a research chemical is not intended for human ...
with no suitable therapeutic indications, likely because such drugs would induce the potentially highly dangerous
hyperphenylalaninemia or
phenylketonuria
Phenylketonuria (PKU) is an inborn error of metabolism that results in decreased metabolism of the amino acid phenylalanine. Untreated PKU can lead to intellectual disability, seizures, behavioral problems, and mental disorders. It may also r ...
.
Tyrosine hydroxylase
Tyrosine hydroxylase or tyrosine 3-monooxygenase is the enzyme responsible for catalyzing the conversion of the amino acid L-tyrosine to L-3,4-dihydroxyphenylalanine (L-DOPA). It does so using molecular oxygen (O2), as well as iron (Fe2+) and ...
inhibitors like
metirosine, which is used in the treatment of
pheochromocytoma
Pheochromocytoma is a rare tumor of the adrenal medulla composed of chromaffin cells and is part of the paraganglioma (PGL) family of tumors, being defined as an intra-adrenal PGL. These neuroendocrine tumors can be sympathetic, where they relea ...
as a
sympatholytic or
antihypertensive
Antihypertensives are a class of drugs that are used to treat hypertension (high blood pressure). Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke, heart failure, kidney failure and myocardial infa ...
agent.
Dopaminergic neurotoxins
Dopaminergic neurotoxins like
6-hydroxydopamine
Oxidopamine, also known as 6-hydroxydopamine (6-OHDA) or 2,4,5-trihydroxyphenethylamine, is a synthetic monoaminergic neurotoxin used by researchers to selectively destroy dopaminergic and noradrenergic neurons in the brain.
The main use for ox ...
(6-OHDA) and
MPTP
MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) is an organic compound. It is classified as a tetrahydropyridine. It is of interest as a precursor to the monoaminergic neurotoxin MPP+, which causes permanent symptoms of Parkinson's dise ...
are used in
scientific research
The scientific method is an empirical method for acquiring knowledge that has been referred to while doing science since at least the 17th century. Historically, it was developed through the centuries from the ancient and medieval world. The ...
to
lesion
A lesion is any damage or abnormal change in the tissue of an organism, usually caused by injury or diseases. The term ''Lesion'' is derived from the Latin meaning "injury". Lesions may occur in both plants and animals.
Types
There is no de ...
the dopamine system and study the biological role of dopamine.
Miscellaneous agents
Adamantane derivatives
Amantadine
Amantadine, sold under the brand name Gocovri among others, is a medication used to treat dyskinesia associated with parkinsonism and influenza caused by type A influenzavirus, though its use for the latter is no longer recommended because ...
has dopaminergic effects through uncertain
mechanisms of action.
It is structurally related to other
adamantane
Adamantane is an organic compound with formula C10H16 or, more descriptively, (CH)4(CH2)6. Adamantane molecules can be described as the fusion of three cyclohexane rings. The molecule is both rigid and virtually stress-free. Adamantane is the mo ...
s like
bromantane and
rimantadine, which also have dopaminergic actions.
Bromantane can upregulate
tyrosine hydroxylase
Tyrosine hydroxylase or tyrosine 3-monooxygenase is the enzyme responsible for catalyzing the conversion of the amino acid L-tyrosine to L-3,4-dihydroxyphenylalanine (L-DOPA). It does so using molecular oxygen (O2), as well as iron (Fe2+) and ...
(TH) and thereby increase dopamine production and this might be involved in its dopaminergic effects. Amantadine can upregulate TH similarly, but as with bromantane, it is unclear whether this is involved in or responsible for its dopaminergic actions.
Amantadine is used in the treatment of
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...
,
levodopa-induced dyskinesia
Levodopa-induced dyskinesia (LID) is a form of dyskinesia associated with levodopa (l-DOPA), used to treat Parkinson's disease. It often involves hyperkinetic movements, including chorea, dystonia, and athetosis.
In the context of Parkinson's di ...
, and
fatigue
Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself.
Fatigue (in the medical sense) is sometimes associated wit ...
in
multiple sclerosis
Multiple sclerosis (MS) is an autoimmune disease resulting in damage to myelinthe insulating covers of nerve cellsin the brain and spinal cord. As a demyelinating disease, MS disrupts the nervous system's ability to Action potential, transmit ...
. It has also been used in the treatment of
disorders of consciousness
Disorders of consciousness are medical conditions that inhibit consciousness. Some define disorders of consciousness as any change from complete self-awareness to inhibited or absent self-awareness and arousal. This category generally includes m ...
,
disorders of diminished motivation
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 ...
, and
brain injuries. The drug is being studied in the treatment of
depression and
attention deficit hyperactivity disorder
Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by symptoms of inattention, hyperactivity, impulsivity, and emotional dysregulation that are excessive and pervasive, impairing in multiple con ...
(ADHD) as well.
Diphenylpiperidines
4,4-Diphenylpiperidines including
budipine and
prodipine
Prodipine (; developmental code name BY-101) is an experimental drug, experimental antiparkinsonian agent of the phenylpiperidine, 4,4-diphenylpiperidine series related to budipine which was never marketed. It was the predecessor of budipine an ...
are effective in the treatment of
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...
.
Their
mechanism of action
In pharmacology, the term mechanism of action (MOA) refers to the specific biochemical Drug interaction, interaction through which a Medication, drug substance produces its pharmacological effect. A mechanism of action usually includes mention o ...
is unknown but they act as indirect dopaminergic agents.
They have distinct effects from other antiparkinsonian agents and dopaminergic drugs.
Other miscellaneous agents
Aspirin
Aspirin () is the genericized trademark for acetylsalicylic acid (ASA), a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and inflammation, and as an antithrombotic. Specific inflammatory conditions that aspirin is ...
upregulates
tyrosine hydroxylase
Tyrosine hydroxylase or tyrosine 3-monooxygenase is the enzyme responsible for catalyzing the conversion of the amino acid L-tyrosine to L-3,4-dihydroxyphenylalanine (L-DOPA). It does so using molecular oxygen (O2), as well as iron (Fe2+) and ...
and increases dopamine production.
Others such as
hyperforin
Hyperforin is a phytochemical produced by some of the members of the plant genus ''Hypericum'', notably ''Hypericum perforatum'' (St John's wort). Hyperforin may be involved in the pharmacology, pharmacological effects of St. John's wort, specifi ...
and
adhyperforin (both found in ''
Hypericum perforatum
''Hypericum perforatum'', commonly known as St. John's wort (sometimes perforate St. John's wort or common St. John's wort), is a flowering plant in the family Hypericaceae. It is a hairless, Perennial, perennial herb with woody Root, roots, y ...
'' St. John's Wort),
L-theanine
Theanine , also known as L-theanine, L-gamma-glutamylethylamide, or ''N''5-ethyl-L-glutamine, is a non-proteinogenic amino acid similar to the proteinogenic amino acids L-glutamate and L-glutamine. It is produced by certain plants such as t ...
(found in ''
Camellia sinensis
''Camellia sinensis'' is a species of evergreen shrub or small tree in the flowering plant family Theaceae. Its leaves, leaf buds, and stems can be used to produce tea. Common names include tea plant, tea shrub, and tea tree (unrelated to ''Me ...
'', the tea plant), and
''S''-adenosyl-L-methionine (SAMe).
See also
*
Adrenergic
Adrenergic means "working on adrenaline (epinephrine) or noradrenaline (norepinephrine)" (or on their receptors). When not further qualified, it is usually used in the sense of enhancing or mimicking the effects of epinephrine and norepinephrine ...
*
Cholinergic
Cholinergic agents are compounds which mimic the action of acetylcholine and/or butyrylcholine. In general, the word " choline" describes the various quaternary ammonium salts containing the ''N'',''N'',''N''-trimethylethanolammonium cation ...
*
GABAergic
In molecular biology and physiology, something is GABAergic or GABAnergic if it pertains to or affects the neurotransmitter gamma-aminobutyric acid (GABA). For example, a synapse is GABAergic if it uses GABA as its neurotransmitter, and a GABAergic ...
*
Histaminergic
*
Serotonergic
References
{{Neuromodulation
Dopamine