Racetam
Encyclopedia
Nootropic
Nootropics , also referred to as smart drugs, brain steroids, memory enhancers, cognitive enhancers, and intelligence enhancers, are drugs, supplements, nutraceuticals, and functional foods that improve mental functions such as cognition, memory, intelligence, motivation, attention, and concentration...
drugs
Psychoactive drug
A psychoactive drug, psychopharmaceutical, or psychotropic is a chemical substance that crosses the blood–brain barrier and acts primarily upon the central nervous system where it affects brain function, resulting in changes in perception, mood, consciousness, cognition, and behavior...
that share a pyrrolidone nucleus.
Mechanism
There is no generally accepted mechanism for racetams. They generally show no affinity for the most important receptors, although modulation of most important central neurotransmitterNeurotransmitter
Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to...
s, including acetylcholine and glutamate have been reported. Although aniracetam and nebracetam show affinity for muscarinic receptors, only nefiracetam
Nefiracetam
Nefiracetam is a nootropic antidementia drug of the racetam family.Nefiracetam's cytoprotective actions are mediated by enhancement of GABAergic, cholinergic, and monoaminergic neuronal systems that give antiamnesia effects to the Alzheimer's type and cerebrovascular type of dementia.Nefiracetam...
shows it at the nanomolar range. Modulation of protein synthesis and protein Kinase C could be a mechanism. Modification of membrane-located mechanisms of central signal transduction is another hypothesis.
Like ampakines, many racetams are positive allosteric modulators for the AMPA receptor
AMPA receptor
The α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor is a non-NMDA-type ionotropic transmembrane receptor for glutamate that mediates fast synaptic transmission in the central nervous system . Its name is derived from its ability to be activated by the artificial glutamate analog AMPA...
. Other potent cognitive enhancers in development are also positive allosteric modulators for the AMPA receptor
AMPA receptor
The α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor is a non-NMDA-type ionotropic transmembrane receptor for glutamate that mediates fast synaptic transmission in the central nervous system . Its name is derived from its ability to be activated by the artificial glutamate analog AMPA...
.
Racetams are understood to work by activating glutamate receptor
Glutamate receptor
Glutamate receptors are synaptic receptors located primarily on the membranes of neuronal cells. Glutamate is one of the 20 amino acids used to assemble proteins and as a result is abundant in many areas of the body, but it also functions as a neurotransmitter and is particularly abundant in the...
s that are colocalized with cholinergic receptors, thus increasing the firing of the latter. The racetams consequently increase memory capacity by nearly the same method as the acetylcholinesterase inhibitor
Acetylcholinesterase inhibitor
An acetylcholinesterase inhibitor or anti-cholinesterase is a chemical that inhibits the cholinesterase enzyme from breaking down acetylcholine, increasing both the level and duration of action of the neurotransmitter acetylcholine.- Uses :Acetylcholinesterase inhibitors:* Occur naturally as...
s.
Of the cognitive enhancing members of the racetam family, nootropic potency is increased when taken with lecithin
Lecithin
Lecithin is a generic term to designate any group of yellow-brownish fatty substances occurring in animal and plant tissues, and in egg yolk, composed of phosphoric acid, choline, fatty acids, glycerol, glycolipids, triglycerides, and phospholipids .The word lecithin was originally coined in 1847 by...
, choline
Choline
Choline is a water-soluble essential nutrient. It is usually grouped within the B-complex vitamins. Choline generally refers to the various quaternary ammonium salts containing the N,N,N-trimethylethanolammonium cation....
, DMAE or other acetylcholine precursors.
Examples
- PiracetamPiracetamPiracetam is a nootropic drug. Piracetam's chemical name is 2-oxo-1-pyrrolidine acetamide; it shares the same 2-oxo-pyrrolidone base structure with 2-oxo-pyrrolidine carboxylic acid . Piracetam is a cyclic derivative of GABA. It is one of the group of racetams...
- Water-soluble racetam; The first of the racetams to be discovered (in the mid-1960s) - OxiracetamOxiracetamOxiracetam is a nootropic drug of the racetam family.Several animal studies suggest that the substance is safe even when high doses are consumed for a long period of time...
- Water-soluble racetam - AniracetamAniracetamAniracetam is an ampakine and nootropic of the racetam chemical class purported to be considerably more potent than piracetam. It is lipid-soluble and has possible cognition-enhancing effects. It has been tested in animals extensively, Alzheimer's patients, and temporarily-impaired healthy subjects...
- Fat-soluble racetam - PramiracetamPramiracetamPramiracetam is a nootropic dietary supplement derived from piracetam, and is more potent . It belongs to the racetam family of nootropics....
- Fat-soluble racetam - EtiracetamEtiracetamEtiracetam is a nootropic drug of the racetam family. It is racemic; its biologically active enantiomeric form is levetiracetam....
- Levetiracetam - anticonvulsant used to treat epilepsy. It is the S- enantiomer of etiracetam.
- NefiracetamNefiracetamNefiracetam is a nootropic antidementia drug of the racetam family.Nefiracetam's cytoprotective actions are mediated by enhancement of GABAergic, cholinergic, and monoaminergic neuronal systems that give antiamnesia effects to the Alzheimer's type and cerebrovascular type of dementia.Nefiracetam...
- with antidepressant-like activity (M1 acetylcholine receptor agonist) - NicoracetamNicoracetamNicoracetam is a nootropic drug from the racetam family. It shares some structural similarities with aniracetam, but differs mostly in that it has a pyridine ring in place of aniracetam's benzene ring....
- racetam structure bonded to niacin - Phenylpiracetam - "Phenotropil" in Russia, very active racetam congener
- RolziracetamRolziracetamRolziracetam is a nootropic drug of the racetam family.Rolziracetam was found to improve performance on a delayed-response task in aged rhesus monkeys. It has a wide margin of safety in animals and has been evaluated for use in cognitively impaired human subjects....
- NebracetamNebracetamNebracetam is nootropic drug of the racetam family, and an antidepressant ....
- FasoracetamFasoracetamFasoracetam is a nootropic drug of the racetam family....
- ImuracetamImuracetamImuracetam is a nootropic drug of the racetam family....
- ColuracetamColuracetamColuracetam is a nootropic drug of the racetam family. It may also have potential use in prevention and treatment of ischemic retinopathy and retinal and optic nerve injury....
- potential use in prevention and treatment of ischemic retinopathy and retinal and optic nerve injury - DimiracetamDimiracetamDimiracetam is a nootropic drug of the racetam family, derivatives of which may have application in the treatment of neuropathic pain....
- currently being studied in the treatment of neuropathic pain - BrivaracetamBrivaracetamBrivaracetam, the 4-n-propyl analog of levetiracetam, is a racetam derivative with anticonvulsant properties. Brivaracetam is believed to act by binding to the ubiquitous synaptic vesicle protein SV2. Phase II clinical trials in adult patients with refractory partial seizures were promising...
- anticonvulsant properties - SeletracetamSeletracetamSeletracetam is a drug of the racetam family. It is currently being developed by UCB Pharmaceuticals as an anticonvulsant drug. While similar in structure to so-called nootropic drugs, it is not expected to have cognitive enhancing properties....
- anticonvulsant, not expected to be nootropic - BrivaracetamBrivaracetamBrivaracetam, the 4-n-propyl analog of levetiracetam, is a racetam derivative with anticonvulsant properties. Brivaracetam is believed to act by binding to the ubiquitous synaptic vesicle protein SV2. Phase II clinical trials in adult patients with refractory partial seizures were promising...
- anticonvulsant - ColuracetamColuracetamColuracetam is a nootropic drug of the racetam family. It may also have potential use in prevention and treatment of ischemic retinopathy and retinal and optic nerve injury....
- RolipramRolipramRolipram is a PDE4-inhibitor. Like most PDE4-inhibitors, it is an anti-inflammatory drug. Rolipram is being studied as a possible alternative to current antidepressants. Recent studies show that rolipram may have antipsychotic effects...
- antidepressant, anti-inflammatory and possibly antipsychotic drug that improves long term memory and wakefulness, and is neuroprotective (in animal studies)
Side effects of Levetiracetam
A 2005 review of the benefits and risks of levetiracetam found that the effects reported which differed from placebo group included somnolence, asthenia, dizziness, and flu-like symptoms. Irritability, agitationAgitation
Agitation may refer to:* Agitation , putting into motion by shaking or stirring* Emotional state of excitement or restlessness** Psychomotor agitation, an extreme form of the above, which can be a side effect of antipsychotic medication...
, anger and aggressive behavior have also been reported and appear to be more common among learning disabled. Slightly lower white blood and red blood cell count have been observed. Levetiracetam still exhibits a favorable safety profile. Interactions with other drugs have been reported and it is metabolized independently of the cytochrome P450 enzyme system.
Levetiracetam inhibits communication between the two halves of the brain, thus being efficacious in epilepsy. Levetiracetam is unique in this respect. Almost all other racetams promote communication between hemispheres.