Racetam

2-Pyrrolidone

Piracetam

Aniracetam

Oxiracetam

Pramiracetam

Phenylpiracetam

Racetams are a class of nootropic drugs that share a pyrrolidone nucleus.^{[citation needed]}

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 neurotransmitters, including acetylcholine and glutamate have been reported. Although aniracetam and nebracetam show affinity for muscarinic receptors, only 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. Other potent cognitive enhancers in development are also positive allosteric modulators for the AMPA receptor.^{[citation needed]}

Racetams are understood to work by activating glutamate receptors that are colocalized with cholinergic receptors, thus increasing the firing of the latter.^{[citation needed]} The racetams consequently increase memory capacity by nearly the same method as the acetylcholinesterase inhibitors.^{[citation needed]}

Of the cognitive enhancing members of the racetam family, nootropic potency is increased when taken with lecithin, choline, DMAE or other acetylcholine precursors.^{[citation needed]}

Examples

• Piracetam - Water-soluble racetam; The first of the racetams to be discovered (in the mid-1960s)^{[citation needed]}
• Oxiracetam - Water-soluble racetam
• Aniracetam - Fat-soluble racetam
• Pramiracetam - Fat-soluble racetam
• Etiracetam
• Levetiracetam - anticonvulsant used to treat epilepsy. It is the S- enantiomer of etiracetam.
• Nefiracetam - with antidepressant-like activity (M1 acetylcholine receptor agonist)
• Nicoracetam - racetam structure bonded to niacin
• Phenylpiracetam - "Phenotropil" in Russia, very active racetam congener
• Rolziracetam
• Nebracetam
• Fasoracetam
• Imuracetam
• Coluracetam - potential use in prevention and treatment of ischemic retinopathy and retinal and optic nerve injury
• Dimiracetam - currently being studied in the treatment of neuropathic pain
• Brivaracetam - anticonvulsant properties
• Seletracetam - anticonvulsant, not expected to be nootropic
• Brivaracetam - anticonvulsant
• Coluracetam
• Rolipram - antidepressant, anti-inflammatory and possibly antipsychotic drug that improves long term memory and wakefulness, and is neuroprotective (in animal studies)^{[citation needed]}

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, agitation, 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.