Oxiracetam
Encyclopedia
Oxiracetam 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. However, the mechanism of action
of the racetam
drug family is still a matter of research.
However, no convincing results were obtained from studies where patients suffering from Alzheimer's dementia or organic solvent abuse were given 800 mg of the drug orally twice daily.
The proven effects of the drug are limited to beneficial effects that lead to higher scores in tests for logical performance, attention, concentration, memory and spatial orientation. These tests were performed on patients with mild to moderate dementia, and the doses were 800-2400 mg orally twice a day for one to six months. Improvement has also been seen in patients with exogenic post-concussion syndrome, organic brain syndromes and other dementias. According to V. Gallai et al, oxiracetam is more effective than piracetam for this purpose.
Peak serum levels are reached within one to three hours after a single 800 mg or 2000 mg oral dose, with the maximal serum concentration reaching between 19-31 µg/ml at these doses.
Oxiracetam is mainly cleared renally and thus 84% is excreted unchanged in the urine.
The half-life of oxiracetam in healthy individuals is about 8 hours, whereas it is 10-68 hours in patients with renal impairment.
There is some penetration of the blood-brain barrier
with brain concentrations reaching 5.3% of that in the blood (measured one hour after a single 2000 mg intravenous dose).
Clearance rates range from 9 to 95 ml/min and steady-state concentrations when 800 mg is given twice daily range from 60 µM to 530 µM.
The highest concentrations of oxiracetam is found in the septum pellucidum
, followed by the hippocampus
, the cerebral cortex
and with the lowest concentrations in the striatum after a 200 mg/kg oral dose given to rats.
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...
drug of the racetam
Racetam
Racetams are a class of nootropic drugs 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 neurotransmitters, including acetylcholine and...
family.
Several animal studies suggest that the substance is safe even when high doses are consumed for a long period of time. However, the mechanism of action
Mechanism of action
In pharmacology, the term mechanism of action refers to the specific biochemical interaction through which a drug substance produces its pharmacological effect...
of the racetam
Racetam
Racetams are a class of nootropic drugs 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 neurotransmitters, including acetylcholine and...
drug family is still a matter of research.
Clinical findings
There has been put effort into investigation the possible use of oxiracetam as a medication to attenuate the symptoms of dementia.However, no convincing results were obtained from studies where patients suffering from Alzheimer's dementia or organic solvent abuse were given 800 mg of the drug orally twice daily.
The proven effects of the drug are limited to beneficial effects that lead to higher scores in tests for logical performance, attention, concentration, memory and spatial orientation. These tests were performed on patients with mild to moderate dementia, and the doses were 800-2400 mg orally twice a day for one to six months. Improvement has also been seen in patients with exogenic post-concussion syndrome, organic brain syndromes and other dementias. According to V. Gallai et al, oxiracetam is more effective than piracetam for this purpose.
Pharmacokinetics
Oxiracetam is well absorbed from the gastrointestinal tract with a bioavailability of 68-82% according to one source (E. Perucca et al) and 56% according to another.Peak serum levels are reached within one to three hours after a single 800 mg or 2000 mg oral dose, with the maximal serum concentration reaching between 19-31 µg/ml at these doses.
Oxiracetam is mainly cleared renally and thus 84% is excreted unchanged in the urine.
The half-life of oxiracetam in healthy individuals is about 8 hours, whereas it is 10-68 hours in patients with renal impairment.
There is some penetration of the blood-brain barrier
Blood-brain barrier
The blood–brain barrier is a separation of circulating blood and the brain extracellular fluid in the central nervous system . It occurs along all capillaries and consists of tight junctions around the capillaries that do not exist in normal circulation. Endothelial cells restrict the diffusion...
with brain concentrations reaching 5.3% of that in the blood (measured one hour after a single 2000 mg intravenous dose).
Clearance rates range from 9 to 95 ml/min and steady-state concentrations when 800 mg is given twice daily range from 60 µM to 530 µM.
The highest concentrations of oxiracetam is found in the septum pellucidum
Septum pellucidum
The septum pellucidum , and not to be confused with the medial septum, is a thin, triangular, vertical membrane separating the anterior horns of the left and right lateral ventricles of the brain...
, followed by the hippocampus
Hippocampus
The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...
, the cerebral cortex
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...
and with the lowest concentrations in the striatum after a 200 mg/kg oral dose given to rats.