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.
There has been effort put into investigating 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 ADHD, 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.
Research shows oxiracetam improves hippocampally-mediated learning performance by increasing membrane-bound PKC. When compared to control mice, oxiracetam-treated DBA mice demonstrated a significant increase in spatial learning performance as determined by the Morris task. This increase in performance was correlated to an increase in membrane-bound PKC.
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 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.
^Valzelli, L.; Baiguerra, G.; Giraud, O. (1986). "Difference in learning and retention by Albino Swiss mice. Part III. Effect of some brain stimulants". Methods and findings in experimental and clinical pharmacology8 (6): 337–341. PMID3736279.edit