HEPARINE INJECTION BP 5,000 UNITS/ML

Indications

• Deep vein thrombosis (DVT)
• Pulmonary embolism (PE)
• Myocardial infarction
• Atrial fibrillation with embolization
• Prevention of clot formation during surgeries (e.g., cardiac surgery, orthopedic surgery)
• Patients undergoing hemodialysis

Dosage

Adults: Dosing for heparin varies based on the clinical condition being treated and the route of administration. For therapeutic anticoagulation, an initial bolus followed by a continuous intravenous infusion is common, with adjustments made based on aPTT or anti-factor Xa levels. Refer to specific clinical guidelines for dosing

Mechanism of action

Heparin exerts its anticoagulant effect primarily by activating antithrombin III, which inactivates thrombin and factor Xa. This inhibition prevents the conversion of fibrinogen to fibrin, thereby reducing clot formation. Heparin has a more pronounced effect on factor Xa compared to thrombin when given in lower doses, while higher doses affect both factors more significantly.

Pharmacodynamics

Heparin's anticoagulant effect is dose-dependent, with an immediate onset when administered intravenously. Its activity is monitored via activated partial thromboplastin time (aPTT) or anti-factor Xa levels. The effects of heparin can be reversed with protamine sulfate, which binds to heparin and neutralizes its action.

Pharmacokinetics

Heparin is not absorbed orally and must be administered parenterally. It has a rapid onset of action when given intravenously, with a half-life of approximately 1 to 2 hours, depending on the dose and individual patient factors. Heparin is primarily cleared by the reticuloendothelial system, and its clearance can be affected by factors such as patient weight, renal function, and the presence of other medications.

Contra-indications

• Active bleeding
• Severe thrombocytopenia
• History of heparin-induced thrombocytopenia
• Hypersensitivity to heparin or any of its components
• Severe liver disease

Adverse effects

• Bleeding
• Thrombocytopenia
• Osteoporosis with long-term use
• Hyperkalemia
• Allergic reactions
• Injection site reactions

Interactions

• Other anticoagulants (e.g., warfarin, dabigatran)
• Antiplatelet agents (e.g., aspirin)
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Certain antibiotics (e.g., penicillins and cephalosporins)
• Oral hypoglycemics

Precautions

• Use with caution in patients with renal impairment
• Monitor for signs of bleeding or thrombocytopenia
• Caution in patients with a history of peptic ulcer disease
• Consider dose adjustments in elderly patients
• Avoid intramuscular injections

Pregnancy

Heparin is generally considered safe during pregnancy, but the risks and benefits should be weighed carefully.

Breast-feeding

Heparin is not excreted in significant amounts in breast milk and is considered safe during breastfeeding.

Storage

Store at room temperature, protect from light, and keep out of reach of children.

Formulations

• Heparin sodium injection
• Low molecular weight heparins (e.g., enoxaparin, dalteparin)