Method of administration
By continuous intravenous infusion in 5% glucose or 0.9% sodium chloride or by intermittent intravenous injection, or by subcutaneous injection.
The intravenous injection volume of heparin injection should not exceed 15ml. As the effects of heparin are short-lived, administration by intravenous infusion or subcutaneous injection is preferable to intermittent intravenous injections.
Posology
Prophylaxis of deep vein thrombosis and pulmonary embolism
Adults:
2 hours pre-operatively: | 5,000 units subcutaneously |
followed by: | 5,000 units subcutaneously every 8-12 hours, for 7-10 days or until the patient is fully ambulant. |
No laboratory monitoring should be necessary during low dose heparin prophylaxis. If monitoring is considered desirable, anti-Xa assays should be used as the activated partial thromboplastin time (APTT) is not significantly prolonged.
Elderly:
Dosage reduction and monitoring of APTT may be advisable.
Paediatric population: No dosage recommendations.
Treatment of deep vein thrombosis and pulmonary embolism:
Adults:
Loading dose: | 5,000 units intravenously (10,000 units may be required in severe pulmonary embolism) |
Maintenance: | 1,000-2,000 units/hour by intravenous infusion, or 10,000-20,000 units 12 hourly subcutaneously, or 5,000-10,000 units 4-hourly by intravenous injection. |
Elderly:
Dosage reduction may be advisable.
Children and small adults:
Loading dose: | 50 units/kg intravenously |
Maintenance: | 15-25 units/kg/hour by intravenous infusion, or 250 units/kg 12 hourly subcutaneously, or 100 units/kg 4-hourly by intravenous injection. |
Treatment of unstable angina pectoris and acute peripheral arterial occlusion:
Adults:
Loading dose: | 5,000 units intravenously |
Maintenance: | 1,000-2,000 units/hour by intravenous infusion, or 5,000-10,000 units 4-hourly by intravenous injection. |
Elderly:
Dosage reduction may be advisable.
Children and small adults:
Loading dose: | 50 units/kg intravenously |
Maintenance: | 15-25 units/kg/hour by intravenous infusion, or 100 units/kg 4-hourly by intravenous injection. |
Daily laboratory monitoring (ideally at the same time each day, starting 4-6 hours after initiation of treatment) is essential during full-dose heparin treatment, with adjustment of dosage to maintain an APTT value 1.5-2.5 x midpoint of normal range or control value.
Prophylaxis of mural thrombosis following myocardial infarction
Adults:
12,500 units 12 hourly subcutaneously for at least 10 days.
Elderly:
Dosage reduction may be advisable
In extracorporeal circulation and haemodialysis
Adults:
Cardiopulmonary bypass:
Initially 300 units/kg intravenously, adjusted thereafter to maintain the activated clotting time (ACT) in the range 400-500 seconds.
Haemodialysis and haemofiltration: Initially 1,000-5,000 units,
Maintenance: 1,000-2,000 units/hour, adjusted to maintain clotting time >40 minutes.
Heparin resistance
Patients with altered heparin responsiveness or heparin resistance may require disproportionately higher doses of heparin to achieve the desired effect. Also refer to section 4.4, Special warnings and precautions for use.