Streptokinasa

Streptokinasa – the fibrinolitic drug exerting impact on coagulability of blood and aggregation of thrombocytes.

Pharmacological action of Streptokinasa

The coagulant system of blood represents the cascade of the reactions following one by one. Streptokinasa affects one of blood coagulation links. By the nature it is high cleaning enzyme of a β-hemolitic streptococcus of group C. Connecting to blood protein plasminogen, Streptokinasa forms a complex which activates transition of plasminogen to plasmin (fibrinolysin) – active proteolytic enzyme which dissolves fibrin fibers in blood clots. Plasmin destroys fibrinogen and other factors of coagulation, interfering with formation of a clot. Drug dissolves blood clots as on their surface, and from within.

People for the life repeatedly face a streptococcus, including as the causative agent of various diseases. As a result of interaction with a microorganism the immune system of the person forms protective antibodys which are capable to neutralize activator antigens. Enzyme Streptokinasa is one of streptococcus antigens therefore at its introduction to a blood channel a part of drug is inactivated by protective antibodys of blood. That medicine began to work to destination – to dissolve blood clots, neutralization of antibodies requires its excess quantity.

Streptokinasa activates also fabric a fibrinolysis (that is dissolution of blood clots), and system as blood fibrinogen is split. Thereof in blood the lack of factors of coagulation forms that can provoke bleeding. Medicine is most effective at fresh blood clots which age no more than 12 hours (before consolidation of a clot – retraction).

Streptokinasa is capable to change a hemodynamics at patients with chronic heart failure – it reduces the arterial pressure and the general peripheric resistance of vessels, the minute volume of blood circulation as a result decreases that improves work of a left ventricle, and functional indicators of heart in general. It is proved that use of Streptokinasa reduces risk of death from a thromboembolism of a pulmonary artery and a myocardial infarction in case of use of medicine in the first days for the beginning of a disease. Effect of drug begins right after introduction, the maximum effect is reached in 45 minutes and remains within several hours.

On a biochemical structure Streptokinasa – protein with complex structure therefore the pharmacodynamics it is not studied, just as metabolites and the mechanism of removal from an organism.

Release form

Streptokinasa is issued in the form of the lyophilized powder for injections in bottles on 100 000, 250 000, 750 000, 1 500 000 ME.

Indications to use of Streptokinasa

According to the instruction Streptokinasa is applied in complex therapy of an acute myocardial infarction (in the first days), thromboembolisms of pulmonary and other arteries, including peripheral, at a chronic obliterating endarteritis, obstruction of the arteriovenous shunt, a vein thrombosis of internals and extremities by prescription up to 14 days.

In the emergency ophthalmology Streptokinasa is used for a lysis of blood clots at obstruction of the central vessels of a retina (arteries – till 6-8 o'clock, veins – up to 10 days from the moment of obstruction). Well Streptokinasa and in dissolution of blood clots in arteries after the diagnostic or medical procedures at children proved, including at catheterization of the central vessels at newborns, for washing of intravenous catheters, for example, for a hemodialysis.

Contraindications

As Streptokinasa can provoke life-threatening bleedings, it cannot be applied if it is known that in predydushchiye10 days the patient underwent an operation, an injury, a cardiac tamponade, a puncture of the central vessels, a biopsy, an intubation.

Drug is prohibited and at bleedings or their risk (at blood diseases, ulcers, during periods at women, in the first 18 weeks of pregnancy and after the delivery), at the had brain stroke.

The patients suffering from fibrillation of auricles against the background of a bacterial endocarditis or pathology of the mitral valve have a risk of a cardial embolism therefore their use of Streptokinasa is not recommended too.

In case of the last use of Streptokinasa within the last 6 months in blood the high antiserum capacity to it is observed that can reduce effect of drug and cause allergic reactions of immediate type.

Application instruction of Streptokinasa

This drug for intravenous and intra arterial administration has to be used only in the conditions of a hospital. In order to avoid foaming dissolve the lyophilized Streptokinasa powder, carefully adding solvent and not stirring up a bottle. As solvent it is possible to use normal saline solutions of sodium chloride and glucose, Ringer's solution. Ready solution of Streptokinasa needs to be used within 12 hours. During a thrombolysis of times at 4 o'clock it is necessary to control coagulability of blood (thrombin and partial tromboplastinovy time). Begin introduction with small speed, gradually increasing it, it is better under cover of antihistamines. For use of drug at newborns previously do a neyrosonografiya, and it is desirable for more senior children to define sensitivity to Streptokinasa. If within a year there is a need for a repeated thrombolysis, it is better to carry out it using other trombolitik, for example, of an urokinase.

At a myocardial infarction according to the instruction Streptokinasa is entered intravenously kapelno in a dose of 1,5 million ME or intrakoronarno by 250 000 – 300 000 ME in 30-60 minutes.

In case of an embolism of a pulmonary artery and a deep vein thrombosis - 250 000 ME in 30 minutes. After a shock dose it is necessary to continue a maintenance therapy in various options. One of them – on 100 000 ME of Streptokinasa each hour 3 days in a row.

Dissolution of blood clots in hemodialysis shunts demands introduction  of 10 000 - 25 000 ME of drug to zatrombirovanny department. Duration of treatment should not exceed 5 days. After treatment control of recovery of passability of a vessel is necessary.

Side effects

Streptokinasa according to the instruction is capable to cause such undesirable phenomena as bleedings, arrhythmia, allergic and anaphylactic reactions, thromboembolisms of smaller vessels owing to fragmentation of the main blood clot, biochemical changes of blood, arthritises, vasculites, nausea and vomiting, headaches, etc.