Cytidine-5'-diphosphocholine, CDP-choline or citicoline is an essential intermediate in the biosynthetic process of structural phospholipids in cell membranes, in particular phosphatidylcholine. After oral and parenteral administration, it releases the two main components of citicoline, cytidine and choline. Oral absorption is practically complete, therefore the oral bioavailability is approximately the same as intravenous absorption. After absorption, citicoline is widely distributed in the body, crosses the blood-brain barrier and reaches the central nervous system (CNS), where it is incorporated into the membrane and microsomal phospholipid fraction. Citicoline activates the biosynthesis of structural phospholipids of neuronal membranes, enhances brain metabolism and affects the levels of various neurotransmitters. Thus, citicoline has been experimentally shown to increase the levels of noradrenaline and dopamine in the central nervous system. Thanks to these pharmacological mechanisms, citicoline exerts neuroprotective effects in hypoxic and ischemic conditions, reduces the volume of ischemic lesions, and improves learning and memory performance in animal models of brain aging. In addition, citicoline has been shown to restore the activity of mitochondrial ATPase and membrane Na+/K+ATPase, inhibit the activation of certain phospholipases, and accelerate the reabsorption of cerebral edema in various experimental models. Citicoline has been shown to inhibit the mechanisms of apoptosis associated with cerebral ischemia and certain neurodegeneration models, and to enhance neuroplasticity mechanisms. Citicoline is a safe drug, as shown by the toxicological studies performed, it has no significant systemic cholinergic effects, and is well tolerated. These pharmacological characteristics and mechanisms of action of citicoline suggest that this product may be indicated for the treatment of cerebrovascular diseases, head injuries (HT) of varying severity and cognitive disorders of various causes. In studies conducted in the treatment of HT patients, citicoline was able to accelerate recovery from post-traumatic coma and neurological disorders, achieving a better final functional outcome and shortening the hospital stay in these patients. Citicoline also improved the mnestic and cognitive disorders observed after mild HT, which constitute the so-called post-concussion syndrome. In the treatment of patients with acute ischemic cerebrovascular diseases, citicoline accelerates the recovery of consciousness and motor deficits, achieving a better final outcome and facilitating the rehabilitation of these patients. Another major indication for citicoline is the treatment of cognitive impairment in old age, either due to degenerative diseases (such as Alzheimer's disease) or chronic cerebrovascular disease. In patients with chronic cerebral ischemia, citicoline improves scores on cognitive rating scales, while in patients with senile dementia of the Alzheimer type, it arrests the course of the disease, and neuroendocrine, neuroimmunomodulatory, and neurophysiological benefits have been reported. Citicoline has also been shown to be effective in Parkinson's disease, drug addiction and alcoholism, as well as in amblyopia and glaucoma. No serious adverse events have occurred in any series of patients treated with citicoline, demonstrating the safety of citicoline treatment.
Source: https://pubmed.ncbi.nlm.nih.gov/17171187/
