Streptokinase - a fibrinolytic drug that affects blood coagulation and platelet aggregation.
The pharmacological action of streptokinase
Coagulation is a cascade of reactions, one after another. Streptokinase acts on one of the units of blood coagulation. By its very nature it is a highly purified enzyme β-hemolytic streptococcus Group C. Combining with blood protein plasminogen streptokinase forms a complex which activates plasminogen to plasmin transition (fibrinolysin) - an active proteolytic enzyme that dissolves fibrin fibers in clot. Plasmin breaks down fibrinogen and other clotting factors, preventing the formation of a clot. The drug dissolves blood clots on the surface and inside.
People in my life have repeatedly faced with strep, including both the causative agent of various diseases. As a result of interaction with the organism's immune system forms a protective antibodies that can neutralize the antigens of the pathogen. Streptokinase is a streptococcus antigen, so when administered into the bloodstream of the drug is inactivated by protective antibody levels. To the drug began to operate as intended - to dissolve blood clots, to neutralize the antibodies necessary to excessive amount thereof.
Streptokinase activates fibrinolysis and tissue (i.e. thrombus dissolution), and systemic, have been cleaved fibrinogen levels. Because of this lack of blood coagulation factors formed that can cause bleeding. The drug is most effective when fresh thrombi, whose age is not more than 12 hours (before sealing clot - retraction).
Streptokinase can alter hemodynamics in patients with chronic heart failure - it lowers blood pressure and total peripheral vascular resistance, resulting in reduced minute volume of blood circulation, which improves the work of the left ventricle, and functional performance of the heart as a whole. It is proved that the use of streptokinase reduces the risk of death from pulmonary embolism and myocardial infarction in the case of medication on the first day of onset. Preparation action begins immediately after administration, the maximum effect is achieved within 45 minutes and lasts for several hours.
By biochemical structure Streptokinase - protein with a complex structure, so it has not been studied pharmacodynamics as well as the metabolites and the mechanism of excretion.
Streptokinase is available as a lyophilized powder for injection in vials 100 000 250 000 750 000 1 500 000 IU.
Indications for use of streptokinase
Streptokinase is used according to the instructions in the treatment of acute myocardial infarction (first day), pulmonary embolism and other arteries, including peripheral, chronic occlusive disease, occlusion of arteriovenous shunt, venous thrombosis of internal organs and extremities to the prescription of 14 hours.
In an emergency ophthalmology streptokinase used for thrombolysis in the occlusion of the central retinal vessels (arteries - to 6-8 hours veins - up to 10 days after occlusion). Well proven and streptokinase in dissolving blood clots in the arteries after diagnostic or therapeutic procedures in children, including in the central vascular catheter in newborns, intravenous catheters for washing, for example, for hemodialysis.
Since streptokinase can cause life-threatening bleeding can not be used if it is known that predyduschie10 days, the patient underwent surgery, trauma, cardiac tamponade, puncture of central vessels, biopsy, intubation.
Prohibited drug and bleeding or risk (blood diseases, ulcers, during menstruation in women in the first 18 weeks of pregnancy and after childbirth), with a stroke of the brain.
Patients suffering from atrial fibrillation on a background of bacterial endocarditis, or mitral valve disease is a risk of cardiac embolism, so they have the use of streptokinase is also not recommended.
In the latter case of streptokinase during the previous 6 months in the blood high titer antibodies to it, which can reduce the effect of the drug and cause allergic reactions of the immediate type.
Instructions for use of streptokinase
This drug is for intravenous and intra-arterial administration should only be used in hospital
. To avoid foaming freeze-dried powder is diluted with streptokinase, carefully adding the solvent and shaking the bottle
. As the solvent, use of physiological saline solution and glucose solution, Ringer's
. The prepared solution should be used with streptokinase for 12 hours
. During thrombolysis once every 4 hours is necessary to control blood clotting (thrombin and partial thromboplastin time)
. Begin with the introduction of low speed, gradually increasing its best undercover antihistamines
. For the use of the drug in newborn pre-made cranial ultrasonography, and older children, it is desirable to determine the sensitivity to streptokinase
. If during the year there is a need to re thrombolysis, it is best done with the use of another thrombolytic agent, such as urokinase
Myocardial infarction instructions streptokinase is administered intravenously at a dose of 1, 5 million IU or intracoronary 250,000 - 300,000 IU for 30-60 minutes.
In the case of pulmonary embolism and deep vein thrombosis - 250 000 IU per 30 minutes. After the loading dose should be continued maintenance therapy in a variety of ways. One of them - 100 000 IU streptokinase every hour for 3 consecutive days.
Dissolving blood clots in hemodialysis shunts require injection of 10 000 - 25 000 IU of the preparation in zatrombirovanny department. The duration of treatment should not exceed 5 days. After the treatment is necessary to monitor patency of the vessel.
Streptokinase according to the instructions can cause adverse effects such as bleeding, arrhythmia, allergic and anaphylactic reactions, thromboembolic events of smaller vessels due to the fragmentation of primary thrombus, biochemical changes in the blood, arthritis, vasculitis, nausea and vomiting, headaches, and others.