This document discusses drugs that affect thrombosis, including fibrinolytics and antifibrinolytics. Fibrinolytics such as streptokinase, tissue plasminogen activators (t-PAs), and others work by activating plasminogen to form plasmin, which breaks down fibrin clots. They are used to treat conditions like pulmonary embolism and myocardial infarction. Adverse effects include bleeding. Antifibrinolytics like aminocaproic acid and tranexamic acid competitively inhibit fibrinolysis and are used as adjunctive therapy for bleeding disorders or to prevent rebleeding.

1. Drugs affecting Thrombosis
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3. Fibrinolytics / thrombolytics
• Drugs :
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Streptokinase
Urokinase
Antistreplase
Tissue plasminogen
activators (t-PA)
• Human t-PA
(Alteplase)
• Reteplase
• Tenecteplase

4. Streptokinase
• It is a streptococcal exotoxin ( beta hemolytic streptococci
group C)
MECHANISM OF ACTION:
– It combines with circulating–plasminogen-liberating
plasmin which breaks down fibrin
– No intrinsic enzymatic activity but forms a stable complex
with plasminogen . This complex then converts
uncomplexed plasminogen to active plasmin which causes
hydrolysis of fibrin plugs .
– Plasmin catalyses degradation of fibrinogen as well as
clotting factors

5. USES
– Pulmonary embolism
– Peripheral arterial occlusion ( given intraarterially)
– Venous thrombosis
– Lysis of coronary thrombosis(present use) in acute
myocardial infarction
– Clear occluded arterio venous cannula
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6. • ADVERSE EFFECTS
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Bleeding particularly at the sites of recent trauma.
Hypersensitive reactions
Anaphylaxis(especially when used second time in a patient)
Fever
Hypotension
Arrhythmias.
• PRECAUTIONS
– It should not be used if patient has had previous
streptokinase therapy within the last 12 months
– Blood pressure should be monitored.

7. Dose
- Acute myocardial infarction and pulmonary
embolism:
- IV infusion loading dose : 250,000 units followed
by 100,000 units/hour for 24-72 hours
- this may be preceded by chlorpheniramine 10mg
and hydrocortisone 100mg to reduce allergic
reactions. This is combined with 300mg aspirin
,which should be chewed before swallowing and
followed by 150mg daily.
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8. CONTRAINDICATIONS
– Surgery within 10 days including :
• Organ biopsy
• Serious trauma
– Serious GIT bleeding within 3 months
– History of hypertension
– Hemorrhagic disorders
– Cerebrovascular accident

9. FIBRINOLYTIC INHIBITORS:
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Aminocaproic acid
Tranexamic acid
Phytomenadione
Aprotinin

10. Aminocaproic acid (EACA)
• chemically similar to the amino acid lysine
• It competitively inhibits plasminogen
activation
• rapidly absorbed orally and is cleared from the
body by the kidney.
• usual oral dosage :6 g four times a day.
• When administered intravenously, a 5 g
loading dose should be infused over 30
minutes to avoid hypotension.
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11. Tranexamic acid
• analog of aminocaproic acid
• administered orally with a 15 mg/kg loading
dose followed by 30 mg/kg every 6 hours
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12. Uses of antifibrinolytic drugs
• Adjunctive therapy in hemophilia
• Bleeding from fibrinolytic therapy
• Prophylaxis for rebleeding from intracranial
aneurisms
• Post-surgical bleeding
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13. Adverse effects
• EACA
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Intravascular thrombosis
Hypotension
Bradycardia
Arrhythmia
Rarely myopathy
• Tranexamic acid
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Nausea
Diarrhoea
Headache
Thrombophlebitis
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14. Contraindication
• Disseminated intravascular coagulation
• Genitourinary bleeding of upper tract
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