[Pharmacological neuroprotection in stroke in clinical practice: new perspectives]

Current neuroprotective agents in stroke

What is expected from neuroprotection is to inhibit neuronal death and halt or decelerate the neuronal loss to lower the mortality rates, decrease disability, and improve the quality of life following an acute ischemic stroke. Several agents were described as neuroprotective up to date; however, there is still debate which to use in the neurorehabilitation of stroke patients, in terms of both efficacy and also safety. In this review, we discuss the agents, citicoline, cerebrolysin and MLC901 (NeuroAiD II), the three agents which have started to be used frequently in neurorehabilitation clinics recently in the light of the current literature.

The modern concept of neuroprotective therapy in the acute period of ischemic stroke

In recent years, significant successes have been achieved in the treatment of acute ischemic stroke. Given the trend towards an increase in the proportion of patients undergoing intravenous thrombolysis and / or mechanical thrombectomy, the question justifies: is there place for neuroprotective therapy (NT) in the era of active introduction of reperfusion treatment? The review discusses the main mechanisms of brain damage in ischemia / reperfusion and the leading neuroprotective strategies studied in clinical trials. Neuroprotective approaches to suppress excitotoxicity, oxidative and nitrosative stress are presented. The clinical efficacy of magnesium sulfate, uric acid, and edaravone is discussed. Non-pharmacological methods of neuroprotection have been characterized, including remote ischemic conditioning, therapeutic hypothermia and neurostimulation. NT in a situation of impossibility of cerebral reperfusion is discussed. The results of randomized clinical trials and meta-analyzes on citicoline (ceraxon) are analyzed. A clinical case is presented illustrating the management of a patient for whom reperfusion therapy was not feasible due to the course of the disease. In the era of the active development of reperfusion methods for the treatment of ischemic stroke, the goal-setting of NT has changed: it is intended to expand the possibilities of application and increase the effectiveness of intravenous thrombolysis and/or mechanical thrombectome, as well as neutralize their negative reperfusion effects. The main targets for NT remain excitotoxicity, oxidative and nitrosative stress. On the other hand, the real clinical situation associated with the low frequency of reperfusion technology in our country necessitates the use of neuroprotectors effective in this category of patients. In this regard, the administration of ceraxon increases the chances of achieving functional independence. The most effective use of the drug from the first day of the disease at a dose of 2000 mg per day intravenously for at least 4-6 weeks with further long-term oral administration at a dose of 1000 mg per day.

[Pharmacokinetic properties of an innovative nootropic agent based on a derivative of 3,7-diazabicyclo[3.3.1]nonane]

The pharmacokinetics and bioavailability of a derivative of 3,7-diazabicyclo[3.3.1]nonane exhibiting a nootropic effect, were studied after a single dose to rats. The pharmacokinetics of the compound was studied after oral and intravenous administration to 270 male rats Sprague Dawley at doses of 2.5 mg/kg, 13 mg/kg and 25 mg/kg. Its distribution in organs and tissues (brain, thymus, heart, lungs, liver, kidneys, and spleen) was also investigated. It was found that after a single intravenous administration, the investigated substance was determined in the blood of animals for 24 h; the half-life was 4.69 h. The relative bioavailability of the 3,7-diazabicyclo[3.3.1]nonane derivative after oral administration was 42.3%, thus suggesting the prospect of creating dosage forms for oral administration. After a single oral administration, the dose dependence of AUC0-t was exponential. The substance is characterized by heterogeneous distribution in the body with preferential accumulation mainly in well-vascularized tissues.

Neuroenhancement and neuroprotection by oral solution citicoline in non-arteritic ischemic optic neuropathy as a model of neurodegeneration: A randomized pilot study

Purpose

To evaluate whether treatment with Citicoline in oral solution (OS-Citicoline) would increase visual function, retinal ganglion cells (RGCs) function, and neural conduction along visual pathways (neuroenhancement), and/or induce preservation of RGCs fibers’ loss (neuroprotection) in non-arteritic ischemic optic neuropathy (NAION), a human model of neurodegeneration.

Methods

Thirty-six patients with NAION and 20 age-matched controls were enrolled. Nineteen NAION patients received 500 mg/day of OS-Citicoline for a 6-month period followed by 3-month of wash-out (NC Group); 17 NAION patients were not treated (NN Group) from baseline to 9 months. In all subjects at baseline, and in NC and NN eyes at 6 and 9 months of follow-up, we assessed Visual Acuity (VA), Pattern Electroretinogram (PERG), Visual Evoked Potentials (VEP), retinal nerve fiber layer thickness (RNFL-T), and Humphrey 24–2 visual field mean deviation (HFA MD). Mean differences were statistically evaluated with ANOVA between Groups, and linear correlations were analysed with Pearson’s test.

Results

At 6 months, significant differences between groups for all parameters were observed (ANOVA, p<0.01). In NC eyes, VA increased, PERG responses increased, VEP recordings improved and were significantly correlated with increases in HFA MD (p<0.01), and RNFL-T was unmodified or improved. In contrast, in NN eyes, VA, PERG, VEP responses, RNFL-T, and HFA MD were further worsened. Significant differences were still present at 9-month follow-up in the NN Group and after 3 months of OS-Citicoline wash-out in NC eyes.

Conclusions

OS-Citicoline treatment induced neuroenhancement (improvement in RGCs function and neural conduction along visual pathways related to improvement of visual field defects) and neuroprotection (unmodified or improved RNFL morphological condition) in a human model of NAION involving fast RGCs degeneration.

Trial registration

ClinicalTrials.gov NCT03758118.