Introduction
A class of drugs called thrombolytics or fibrinolytic manages blood clots formed during hemostasis (when the blood flow halts). This class of medications treats blood clots by disintegrating them. The drugs that belong to this class of drugs help treat various conditions, such as acute peripheral artery occlusion, deep vein thrombosis, pulmonary embolism, acute ischemic stroke, acute peripheral arterial occlusion, and acute myocardial infarction (heart attack).
What Is Anistreplase?
Anistreplase, also known as anisoylated plasminogen streptokinase activator complex or APSAC, is used to break blood clots in critical medical conditions such as strokes and heart attacks. When used within three hours of the onset of acute myocardial infarction symptoms, the medication promotes the patency of the coronary artery by protecting the myocardial (heart) tissue and left ventricular function. It is administered intravenously (I.V.), and the recommended dose is 30 units, slowly distributed over two to five minutes.
What Is the Composition of Anistreplase (APSAC)?
Anistreplase is a complex combination with equimolar amounts of the following components-
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Bacterial Streptokinase - It is acylated to shield the enzyme's active site. Acylation refers to the chemical process in which one or more acyl groups are added to the compound. In chemistry, acyl groups are a type of functional group found in organic compounds.
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Lys-Plasminogen - It is a purified human plasminogen. Plasminogen is a form of protein (glycoprotein) and is synthesized in the liver. It is the precursor of plasmin, which helps in the degradation of fibrin and the breakdown of clots.
How Does Anistreplase (APSAC) Work?
Anistreplase (APSAC) is a complex mixture of Streptokinase and lys-plasminogen (purified human plasminogen), with the addition of a p-anisoyl group (it temporarily guards the catalytic center of the enzyme complex). Upon intravenous injection (I.V.), this compound undergoes deacylation (a chemical process associated with the removal of acyl groups from a compound) to produce an active complex that changes plasminogen (an inactive form of plasmin) into plasmin. Plasmin has a fibrinolytic (breaks down fibrin within blood clots) function, eliminating blood clots or arterial blockages.
What Is Anistreplase (APSAC) Indicated For?
It is indicated for the conditions-
1. Myocardial Infarction (MI): It is commonly known as a heart attack. It is a severe medical condition that usually occurs when an artery or blood vessel supplying the heart has plaque (fatty and waxy substance) built up within its walls and that plaque suddenly breaks. When the plaque suddenly breaks or dislodges from the blood vessel wall, it causes injury to the walls of the blood vessels and leads to bleeding within the blood vessels. In order to cease this bleeding, platelets act together and form a blood clot. It is this blood clot that prevents the blood from flowing through and reaching the heart muscles. This reduced or diminished blood flow further starves the heart tissue of nutrients and oxygen, causing cardiac ischemia. Eventually, the heart tissue dies, leading to a heart attack.
2. Pulmonary Embolism: It is a condition in which a blood clot develops within the pulmonary arterial circulation. The most common causes of a pulmonary embolism are:
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Deep Vein Thrombosis - A condition in which a thrombus or blood clot forms within the deep veins of the lower extremities.
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Air Embolism - When air or gas is introduced into the circulatory system, an air embolism develops. It is also known as a gas embolism. It can develop iatrogenically through interventional procedures such as catheter placement. It has also been reported as a complication from various circumstances, including scuba diving, trauma (blunt and penetrating), and childbirth. The patient's symptoms could range from being asymptomatic to myocardial collapse and death.
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Fracture of the Long Bones - Fractures of the long bones can lead to fat embolism. When the long bone fractures, several fat globules are released. These fat globules can travel to the lung and eventually obstruct the pulmonary vessels. The fat globules can also travel to other locations, such as the brain (causing cerebral fat embolism) and dermal or skin capillaries. The common symptoms associated with fat embolism are-
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Dyspnea (shortness of breath).
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Skin rash (often found around the neck, head, and chest).
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Tachypnea (rapid breathing).
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Neurological symptoms such as confusion, seizures, and headache.
How Is Anistreplase (APSAC) Stored and Discarded?
Anistreplase (APSAC) is stored between 2 and 8 degrees Celsius (36 degrees Fahrenheit to 46 degrees Fahrenheit). If the solution is not administered within 30 minutes of reconstitution, it should be discarded. The disposal of Anistreplase (APSAC) should be in accordance with local guidelines and medical regulatory bodies.
What Is the Recommended Dose of Anistreplase (APSAC)?
The recommended dose of Anistreplase (APSAC) is 30 units intravenously (I.V.), and it should be administered over two to five minutes.
What Are the Side Effects Associated With Anistreplase (APSAC)?
The following side effects can be seen in individuals administered with Anistreplase-
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Bradycardia (slow heart rate).
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Facial flushing.
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Fever.
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Hives.
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Skin rash.
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Cardiac arrhythmia (irregular heartbeats).
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Minor bleeding or hematoma formation at the site of injection.
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Transient hypotension (temporary drop in blood pressure).
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Dizziness.
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Cholesterol embolization syndrome (CES) or purple-toe syndrome (a condition in which cholesterol crystals are dispersed from a ruptured atherosclerotic plaque, leading to embolization in the smaller distant blood vessels).
Who Should Not Take Anistreplase (APSAC)?
Anistreplase is contraindicated in individuals who have-
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An intracranial tumor.
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Bleeding disorders.
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History of stroke (in the two months before taking Anistreplase).
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Hypersensitivity to Streptokinase.
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Active internal bleeding (for example, peptic ulcer, gastric ulcer).
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Severe or uncontrolled hypertension.
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History of intracranial or intraspinal surgery ((in the two months before taking Anistreplase).
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Aneurysms (abnormal bulges within the blood vessels' walls).
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Aortic valve (A.V.) malfunctions.
What Makes Anistreplase (APSAC) Unique?
Like Streptokinase, Anistreplase(APSAC) does not differentiate between circulating and fibrin-bound plasminogen. Anistreplase (APSAC) produces a systemic lytic state (the body gets activated for fibrin degradation). Similarly, allergic reactions and hypotension (low blood pressure) are just as frequent with Anistreplase (APSAC) as with Streptokinase. Anistreplase (APSAC) is unique because it demonstrates excellent stability in the blood compared to Streptokinase. This is brought on by a slowed breakdown rate and diminished neutralization by plasma inhibitors.
Conclusion
Anistreplase (APSAC) is a drug that is used in thrombolytic therapy. Thrombolytic therapy uses lytics or "clot busters" to dissolve blood clots that can block the major arteries and veins (blood vessels) and pose potentially severe or life-threatening complications. Anistreplase creates a systemic fibrinolytic reaction, just like other thrombolytic drugs. It has a plasma-half-life of about 88 to 112 minutes which is longer than most other thrombolytic drugs. It can be easily administered and valuable for patients with suspected acute myocardial infarction (heart attack). For the therapy to be successful, it should be started immediately before any irreversible damage sets in.
