Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cytidine 5'-diphosphocholine, CDP-choline or citicoline, is an essential intermediate in the biosynthetic pathway of the structural phospholipids of cell membranes, especially in that of phosphatidylcholine. Upon oral or parenteral administration, CDP-choline releases its two principle components, cytidine and choline. When administered orally, it is absorbed almost completely, and its bioavailability is approximately the same as when administered intravenously. Once absorbed, the cytidine and choline disperse widely throughout the organism, cross the blood-brain barrier and reach the central nervous system (CNS), where they are incorporated into the phospholipid fraction of the membrane and microsomes. CDP-choline activates the biosynthesis of structural phospholipids in the neuronal membranes, increases cerebral metabolism and acts on the levels of various neurotransmitters. Thus, it has been experimentally proven that CDP-choline increases noradrenaline and dopamine levels in the CNS. Due to these pharmacological activities, CDP-choline has a neuroprotective effect in situations of hypoxia and ischemia, as well as improved learning and memory performance in animal models of brain aging. Furthermore, it has been demonstrated that CDP-choline restores the activity of mitochondrial ATPase and of membranal Na+/K+ ATPase, inhibits the activation of phospholipase A2 and accelerates the reabsorption of cerebral edema in various experimental models. CDP-choline is a safe drug, as toxicological tests have shown; it has no serious effects on the cholinergic system and it is perfectly tolerated. These pharmacological characteristics, combined with CDP-choline's mechanisms of action, suggest that this drug may be suitable for the treatment of cerebral vascular disease, head trauma of varying severity and cognitive disorders of diverse etiology. In studies carried out on the treatment of patients with head trauma, CDP-choline accelerated the recovery from post-traumatic coma and the recuperation of walking ability, achieved a better final functional result and reduced the hospital stay of these patients, in addition to improving the cognitive and memory disturbances which are observed after a head trauma of lesser severity and which constitute the disorder known as postconcussion syndrome. In the treatment of patients with acute cerebral vascular disease of the ischemic type, CDP-choline accelerated the recovery of consciousness and motor deficit, attaining a better final result and facilitating the rehabilitation of these patients. The other important use for CDP-choline is in the treatment of senile cognitive impairment, which is secondary to degenerative diseases (e.g., Alzheimer's disease) and to chronic cerebral vascular disease. In patients with chronic cerebral ischemia, CDP-choline improves scores on cognitive evaluation scales, while in patients with senile dementia of the Alzheimer's type, it slows the disease's evolution. Beneficial neuroendocrine, neuroimmunomodulatory and neurophysiological effects have been described. CDP-choline has also been shown to be effective as co-therapy for Parkinson's disease. No serious side effects have been found in any of the groups of patients treated with CDP-choline, which demonstrates the safety of the treatment.
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PMID:CDP-choline: pharmacological and clinical review. 870 78

Lessions from epidemiological studies. The Clinical Trial Group for Neurosurgery of the University of California San Diego (UCSD) is involved in epidemiological studies and trials of new pharmacological agents in traumatic brain injury. A great number (> 10,000) of patients has been prospectively analyzed forming an integrated database for further purposes. The development of these databases is based on earlier work by the European Neurosurgeons Jennett and Braakmann and the US-Traumatic Coma Data Bank Study. These studies allowed for the development of sophisticated data collection instruments which were used in the international Tirilizad Trials which enrolled over 1,100 patients. A major observation from that trial was that pretreatment hypotension or hypoxia could be unbalanced even in a large two arm blinded study. Another issue of the tirilazad trial was the influence of gender affecting not only outcome but also drug metabolism. Similar experiences were gathered with the phase-III trial on the competitive NMDA-receptor antagonist selfotel, which interferes with the excitotoxic amino acid glutamate as mediator of secondary brain damage, as ischemia-induced neuronal degeneration. Unfortunately, the trial, already underway, had to be prematurely aborted, since concurrent stroke studies with enrollment of nonintubated patients on low-dose selfotel revealed an increased number of deaths and other adverse events. A retrospective analysis did not confirm that Selfotel was associated with an increased mortality in TBI, but there was also no evidence that the drug was efficacious. A problem here was that a major portion of patients did not have intracranial mass lesions (contusion, subdural haematoma) on CT, questioning whether these had a treatment responsive brain injury. Both studies on tirilazad or selfotel underscore the significance of well designed and conducted phase-I and -II trials to characterize the pharmacokinetics of the agent, to confirm availability of drug in the brain, and to identify a sufficient number of patients with lesions responding to the drug. A major issue is the blood-brain barrier permeability of the agent under study. Further, the phenomenon of secondary deterioration - neurological worsening - turned out as a powerful predictor of poor outcome. The findings and conclusions of both clinical trials (tirilazad, selfotel) were utilized for a subsequent patient study on CP101-606 in consultation with the Pfizer company, the US Brain Injury Consortium, and the San Diego Clinical Trial Group. The patient population was a priori selected towards responsiveness of the brain lesions to the treatment. The major conclusions are: I Development of therapeutic regimens targeted towards the mechanisms of brain injury. II Availability of adequate preclinical data. III Directing treatment towards an appropriate patient population. IV Central gathering and interpretation of the neuroradiological findings. V Monitoring of trial center performance. VI Stratification and pre-trial prognostic analysis for identification of subgroups.
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PMID:Lessons from epidemiologic studies in clinical trials of traumatic brain injury. 1533 8