Neuroprotectants and prevention of ischemic stroke

Prevention of thrombosis and ischemic stroke

To prevent the development of ischemic stroke, it is essential to reliably prevent thrombus formation within the vascular bed. For this purpose, modern clinical practice traditionally prescribes two major groups of drugs that affect the hemostatic system.

The first group consists of antiplatelet agents. These include widely known drugs such as acetylsalicylic acid, clopidogrel, as well as ticlopidine and dipyridamole. Their primary pharmacological task is to prevent the pathological aggregation of platelets in the early stages of thrombus formation.

The second group comprises anticoagulants. These agents directly interfere with the plasma blood coagulation cascade.

However, the use of these potent drugs is always associated with significant clinical limitations. The most formidable risk of antithrombotic therapy is the provocation of intracranial hemorrhage. Therefore, any threat of hemorrhagic stroke is an absolute contraindication to prescribing these drug groups. The attending physician must always maintain a strict balance between the risk of worsening ischemia and the risk of fatal bleeding.

Combination therapy for cerebral ischemia

When ischemic cerebrovascular disorders have already occurred, monotherapy with a single drug is often insufficient. In such complex situations, combination drugs come to the rescue, a prominent example being Instenon. Its high therapeutic efficacy is explained by the pronounced pharmacological synergy of three active components, each with its own specific site of action.

1. Hexobendine. This component is responsible for the rapid relief of vascular spasm (spasmolytic action). In addition, it has a proven coronary-dilating effect, which positively impacts the patient's systemic hemodynamics.
2. Etamivan. A substance with a pronounced analeptic profile. It actively stimulates the central nervous system, maintaining the viability and activity of neuronal networks under conditions of acute oxygen deprivation.
3. Etofylline (also known in pharmacology as hydroxyethyltheophylline). Its key function in this combination is the targeted improvement of cerebral blood flow, which is critically important for the adequate delivery of oxygen and nutrients to ischemic brain tissues.

Neuroprotective therapy

Neuroprotective therapy represents a distinct and highly important vector in the comprehensive treatment of cerebral ischemia. Its fundamental goal is to artificially increase the resistance of nerve cells (neurons) to severe hypoxic conditions. To achieve this ambitious goal, drugs from entirely different pharmacological groups are used, acting on various links of the pathogenesis of ischemic injury.

• Effect on tissue metabolism. A striking example of this approach is sodium oxybate. This drug is capable of restructuring brain metabolism so that nervous tissues tolerate oxygen deprivation much more easily while preserving their structure.
• Blockade of excitotoxicity. In acute ischemia, a massive release of excitatory amino acids occurs, primarily glutamate, which literally "overexcites" and kills neurons. NMDA receptor antagonists (e.g., dizocilpine) effectively block this detrimental action, preventing cell death.
• Regulation of calcium metabolism. Calcium channel blockers come to the fore here. They are unique in providing a potent dual therapeutic effect. On the one hand, they dilate blood vessels and improve local blood flow. On the other hand, they provide true cellular neuroprotection by sharply reducing the pathological influx of calcium ions into damaged cells.
• Other neuroprotective agents. The arsenal of neurologists and pharmacologists also includes vinpocetine, a drug that, in addition to its well-known vascular effects, possesses reliably proven neuroprotective properties.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Mechanisms of action of anticoagulants and their effect on the coagulation cascade.
• Pharmacodynamics of individual antiplatelet agents (dipyridamole, ticlopidine, clopidogrel).
• The phenomenon of excitotoxicity and the pathological role of glutamate in ischemia.
• Metabolic effects of sodium oxybate under conditions of oxygen deprivation.

Other topics in the section "Drugs used for cerebral circulatory disorders"

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