A GABA receptor agonist is a drug that is an

agonist An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an R ...

for one or more of the GABA receptors, producing typically

sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or Psychomotor agitation, excitement. They are central nervous system (CNS) Depressant, depressants and interact with brain activity, causing its decelera ...

effects, and may also cause other effects such as anxiolytic,

anticonvulsant Anticonvulsants (also known as antiepileptic drugs, antiseizure drugs, or anti-seizure medications (ASM)) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also used in the treatme ...

, and

muscle relaxant A muscle relaxant is a drug that affects skeletal muscle function and decreases the muscle tone. It may be used to alleviate symptoms such as muscle spasms, pain, and hyperreflexia. The term "muscle relaxant" is used to refer to two major therapeu ...

effects. There are three receptors of the ''gamma''-aminobutyric acid. The two receptors GABA-α and GABA-ρ are ion channels that are permeable to chloride ions which reduces neuronal excitability. The GABA-β receptor belongs to the class of G-Protein coupled receptors that inhibit adenylyl cyclase, therefore leading to decreased cyclic adenosine monophosphate (cAMP). GABA-α and GABA-ρ receptors produce sedative and hypnotic effects and have anti-convulsion properties. GABA-β receptors also produce similar effects. Furthermore, they lead to changes in gene transcription, and are mainly found in autonomic nervous system centers.

Types

Many commonly used

and anxiolytic drugs that affect the GABA receptor complex are not agonists. These drugs act instead as positive allosteric modulators (PAMs) and while they do bind to the GABA receptors, they bind to an allosteric site on the receptor and cannot induce a response from the neuron without an actual agonist being present. Drugs that fall into this class exert their pharmacodynamic action by increasing the effects that an agonist has when potentiation is achieved. General anaesthetics act primarily as PAMs of GABA-A receptor. Positive allosteric modulators work by increasing the frequency with which the chloride channel opens when an agonist binds to its own site on the GABA receptor. The resulting increase in the concentration of Cl− ions in the postsynaptic neuron immediately hyperpolarizes this neuron, making it less excitable and thus inhibiting the possibility of an

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 ...

. However, some general anaesthetics like propofol and high doses of barbiturates may not only be positive allosteric modulators of GABA-A receptors but also direct agonists of these receptors.

Alcohol Alcohol may refer to: Common uses * Alcohol (chemistry), a class of compounds * Ethanol, one of several alcohols, commonly known as alcohol in everyday life ** Alcohol (drug), intoxicant found in alcoholic beverages ** Alcoholic beverage, an alco ...

is an indirect GABA agonist. GABA is the major inhibitory

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 ...

in the brain, and GABA-like drugs are used to suppress spasms. Alcohol is believed to mimic GABA's effect in the brain, binding to GABA receptors and inhibiting neuronal signaling.

GABA_A

GABA_A receptor ligands include:

Agonists

* Abecarnil * Barbiturates (in high doses) *

Etomidate Etomidate (United States Adopted Name, USAN, International Nonproprietary Name, INN, British Approved Name, BAN; marketed as Amidate) is a short-acting intravenous anaesthetic agent used for the induction of general anaesthesia and sedation for ...

* Eszopiclone * Bamaluzole * Fengabine * GABA * Gabamide * GABOB * Gaboxadol *

Ibotenic acid Ibotenic acid or (''S'')-2-amino-2-(3-hydroxyisoxazol-5-yl)acetic acid, also referred to as ibotenate, is a naturally occurring alpha-amino acid found in certain ''Amanita'' mushrooms, that primarily acts as a potent glutamate receptor agonist ...

* Isoguvacine * Isonipecotic acid * Muscimol *

Phenibut Phenibut, sold under the brand name Anvifen among others, is a central nervous system (CNS) depressant with anxiolytic effects, and is used to treat anxiety, insomnia, and for a variety of other indications. It is usually taken oral administrat ...

* Picamilon * Progabide * Propofol * Quisqualamine * SL 75102 * Thiomuscimol * Topiramate * Zolpidem * Zopiclone

PAMs

s (e.g.,

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

isopropanol Isopropyl alcohol (IUPAC name propan-2-ol and also called isopropanol or 2-propanol) is a colorless, flammable, organic compound with a pungent alcoholic odor. Isopropyl alcohol, an organic polar molecule, is miscible in water, ethanol, an ...

) * Avermectins (e.g., ivermectin) * Barbiturates (e.g., phenobarbital) *

Benzodiazepine Benzodiazepines (BZD, BDZ, BZs), colloquially known as "benzos", are a class of central nervous system (CNS) depressant, depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed t ...

s (e.g.,

diazepam Diazepam, sold under the brand name Valium among others, is a medicine of the benzodiazepine family that acts as an anxiolytic. It is used to treat a range of conditions, including anxiety disorder, anxiety, seizures, alcohol withdrawal syndr ...

alprazolam Alprazolam, sold under the brand name Xanax among others, is a fast-acting, potent tranquilizer of moderate duration within the triazolobenzodiazepine group of chemicals called benzodiazepines. Alprazolam is most commonly prescribed in the ...

) * Bromides (e.g., potassium bromide) *

Carbamate In organic chemistry, a carbamate is a category of organic compounds with the general Chemical formula, formula and Chemical structure, structure , which are formally Derivative (chemistry), derived from carbamic acid (). The term includes orga ...

s (e.g., meprobamate, carisoprodol) *

Chloral hydrate Chloral hydrate is a geminal diol with the formula . It was first used as a sedative and hypnotic in Germany in the 1870s. Over time it was replaced by safer and more effective alternatives but it remained in use in the United States until at ...

, chloralose, petrichloral, and other 2,2,2-trichloroethanol prodrugs * Chlormezanone * Clomethiazole * Dihydroergolines (e.g., ergoloid (dihydroergotoxine)) * Etazepine * Etifoxine * 2-Substituted

phenols In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (− O H) bonded directly to an aromatic hydrocarbon group. The simplest is phenol, . Phenolic compounds ar ...

(e.g., thymol,

eugenol Eugenol is an allyl chain-substituted guaiacol, a member of the allylbenzene class of chemical compounds. It is a colorless to pale yellow, aromatic oily liquid extracted from certain essential oils especially from clove, nutmeg, cinnamon, ...

) * Imidazoles (e.g.,

etomidate Etomidate (United States Adopted Name, USAN, International Nonproprietary Name, INN, British Approved Name, BAN; marketed as Amidate) is a short-acting intravenous anaesthetic agent used for the induction of general anaesthesia and sedation for ...

) *

Kavalactone Kavalactones are a class of lactone compounds found in kava roots and ''Alpinia zerumbet'' (shell ginger) and in several Gymnopilus, Phellinus and Inonotus fungi. Some kavalactones are bioactive. They are responsible for the psychoactive, analges ...

s (found in

kava Kava or kava kava (''Piper methysticum'': Latin 'pepper' and Latinized Ancient Greek, Greek 'intoxicating') is a plant in the Piperaceae, pepper family, native to the Pacific Islands. The name ''kava'' is from Tongan language, Tongan and Marqu ...

) * Loreclezole * Neuroactive steroids (e.g.,

allopregnanolone Allopregnanolone is a natural product, naturally occurring neurosteroid which is made in the body from the hormone progesterone. As a medication, allopregnanolone is referred to as brexanolone, sold under the brand name Zulresso, and used to t ...

, ganaxolone) *

Nonbenzodiazepine Nonbenzodiazepines (), sometimes referred to colloquially as Z-drugs (as many of their names begin with the letter "z"), are a class of psychoactive, depressant, sedative, hypnotic, anxiolytic drugs that are benzodiazepine-like in uses, such as f ...

s (e.g., zaleplon, zolpidem, zopiclone, eszopiclone) * Propofol * Piperidinediones (e.g., glutethimide, methyprylon) * Propanidid * Pyrazolopyridines (e.g., etazolate) * Quinazolinones (e.g., methaqualone) * Skullcap constituents (e.g., Baicalein) *

Stiripentol Stiripentol, sold under the brand name Diacomit, is an anticonvulsant medication used for the treatment of Dravet syndrome - a serious genetic brain disorder. The most common side effects include loss of appetite, weight loss, insomnia (difficu ...

* Disulfonylalkanes (e.g., sulfonmethane, tetronal, trional) * Valerian constituents (e.g., valeric acid, valerenic acid) * Volatile organic compounds (e.g.,

chloroform Chloroform, or trichloromethane (often abbreviated as TCM), is an organochloride with the formula and a common solvent. It is a volatile, colorless, sweet-smelling, dense liquid produced on a large scale as a precursor to refrigerants and po ...

diethyl ether Diethyl ether, or simply ether, is an organic compound with the chemical formula , sometimes abbreviated as . It is a colourless, highly Volatility (chemistry), volatile, sweet-smelling ("ethereal odour"), extremely flammable liquid. It belongs ...

, sevoflurane)