1.
Sources and Structure
1.1
Sources
Phenylpiracetam (structual name (RS)-2-(2-oxo-4-phenylpyrrolidin-1-yl)acetamide and the brandname of either Phenotropil or Carphedon) is a Piracetam derivative that has an additional phenyl group at position 4 of the 2-oxopyrrolidine ring. It is reported (from the manufacturer) to be rapidly and well absorbed due to the enhanced lipophilicity[1] and exerts more anti-amensiac, neuroprotective, and stimulatory effects than does piracetam[2]|published=2007 Mar-Apr|authors=Tiurenkov IN, Bagmetov MN, Epishina VV|journal=Eksp Klin Farmakol][3] and has been reported to enhance physical performance and cold resistance[4] leading to it being included in the banned substances list of the world anti-doping agency (WADA, listed under 4-phenylpiracetam or carphedon as a non-specified stimulant).[5]
Phenylpiracetam is a derivative of piracetam that is touted for being more effective in its anti-amnesiac properties and also possessing psychostimulatory properties
1.2
Structure
Phenylpiracetam is the piracetam structure with an additional phenyl group attached to the pyrrolidone nucleus, albeit at a different steric location than the substituted phenyl groups seen on aniracetam or nefiracetam. Due to the chiral center at the fourth position of the pyrrolidinone ring, it can exist in an S or R isomer; the clinically used form is the racemic mixture.[6]
Phenylpiracetam, as the name implies, is piracetam with a phenyl group attached to it
2.
Pharmacology
2.1
Serum
Injections of 100mg/kg phenylpiracetam to rodents exhibits a half-life of 2.5-3 hours.[7]
30 minutes following a 25mg/kg injection, phenylpiracetam can be detected in the brain at 67-73µg/g and a later test using 100mg/kg noted that approximately 1% of injected phenylpiracetam reached the brain.[6]
No oral pharmacokinetic studies have been conducted yet, but it does appear to be able to cross the blood brain barrier
3.
Neurology
3.1
Cognition
Phenylpiracetam appears to have a series of trials conducted on it (Cited vicariously through this review[1] where four of seven can be located online[8][9][10][11][12]) showing improvement in cognition in persons with cognitive decline from organic causes, with one study noting a minor improvement in cognition in those with epilepsy (youth)[11] and the lone failure coming from a study on traumatic brain injury in youth.[10] These studies used a dosage range between 200mg (100mg twice daily) up to 600mg (200mg thrice daily), and all lasted for one months time.
Symptoms associated with cognitive decline such as anxiety and depression have also been noted to be reduced in open-label trials[9] although the study assessing asthenia (weakness; one of the major reasons phenylpiracetam is prescribed) failed to find a significant effect over control (mild cranial trauma).[10]
One trial not included in the aforementioned review[13] noted improvement in function (physical and cognitive) in person's who suffered from strokes when phenylpiracetam was taken at 400mg daily for one years time.
A relatively large body of research based in Russia (much of which is not available online in the west) appears to support phenylpiracetam for the purpose of attenuating or treating organic cognitive decline. There are no studies currently in youth using phenylpiracetam for cognitive enhancement, and the benefit seen in organic cognitive decline may not extend to physical trauma (like Noopept has been noted in helping)
Only one study has been conducted in otherwise healthy rats, and the R-isomer (not racemic mixture) of phenylpiracetam at 1mg/kg and 10mg/kg improved retention latency in a passive avoidance test by 195% and 185%, respectively.[6]
The R-isomer may have cognitive enhancing properties
3.2
Depression
Depressive symptoms in a forced-swim test in rats have been noted to be greatly reduced with 50-100mg/kg phenylpiracetam, with the R-isomer being more active than the S-isomer.[6] Elsewhere, the depressive symptoms in persons with cognitive decline have been attenuated in an open-label trial with 200mg phenylpiracetam daily (100mg twice daily).[9]
Although not well researched, phenylpiracetam does appear to have anti-depressant properties that are seen with the racemic mixture but more potently with the R-isomer in particular
3.3
Psychostimulation
In rats injected with phenylpiracetam, 10-50mg/kg appears to increase locomotor activity (distance and velocity) mostly due to the R-isomer and without any apparent dose-dependence.[6] The 50mg/kg dose lasted for approximately four hours when the R-isomer was used, and the racemic mixture lasted for two hours.[6]
One study has reported sleep disturbances as a side-effect of phenylpiracetam (Sazonov et al. 2006; not located online but cited via this review[1]), in accordance with the reported psychostimulatory properties. Other trials do not note such a side-effect, and the reason it was detected in this study only is unknown.
Although not well investigated, there is some evidence for the psychostimulatory properties of phenylpiracetam hindering sleep
4.
Inflammation and Immunology
4.1
Interventions
25mg/kg of phenylpiracetam injections daily for five days to rats subsequently given lipopolysaccharide (LPS) injections to aggravate the immune system noted that LPS-induced alterations in DTHR and phagocytosis were normalized with no apparent effect on antibody production.[14] Behavioural alterations from LPS injections (anxiety and sluggishness) were fully abolished.[14]
Although not well researched at this point in time, phenylpiracetam may possess immunosupportive properties under periods of immune stress
