| Do not administer by the intramuscular route. Due to the risk of haematoma, intramuscular injection of other medical preparations should be avoided when the twenty-four hour dose of dalteparin exceeds 5,000 IU.Caution should be exercised in patients in whom there is an increased risk of bleeding complications, e.g. following surgery or trauma, haemorrhagic stroke, severe liver or renal failure, thrombocytopenia or defective platelet function, uncontrolled hypertension, hypertensive or diabetic retinopathy, patients receiving concurrent anticoagulant/antiplatelet agents (see interactions section). Caution shall also be observed at high-dose treatment with dalteparin (such as those needed to treat acute deep vein thrombosis, pulmonary embolism, and unstable coronary artery disease).It is recommended that platelets be counted before starting treatment with Fragmin and monitored regularly. Special caution is necessary in rapidly developing thrombocytopenia and severe thrombocytopenia (<100,000/µl) associated with positive or unknown results of in-vitro tests for anti-platelet antibody in the presence of Fragmin or other low molecular weight (mass) heparins and/or heparin.Fragmin induces only a moderate prolongation of the APTT and thrombin time. Accordingly, dosage increments based upon prolongation of the APTT may cause overdosage and bleeding. Therefore, prolongation of the APTT should only be used as a test of overdosage.Monitoring Anti-Xa Levels Monitoring of Anti-Xa Levels in patients using Fragmin is not usually required but should be considered for specific patient populations such as paediatrics, those with renal failure, those who are very thin or morbidly obese, pregnant or at increased risk for bleeding or rethrombosisWhere monitoring is necessary, laboratory assays using a chromogenic substrate are considered the method of choice for measuring anti-Xa levels. Activated partial thromboplastin time (APTT) or thrombin time should not be used because these tests are relatively insensitive to the activity of dalteparin. Increasing the dose of dalteparin in an attempt to prolong APTT may result in bleeding ( see section 4.9 Overdosage).Patients under chronic haemodialysis with dalteparin need as a rule fewer dosage adjustments and as a result fewer controls of anti-Xa levels. Patients undergoing acute haemodialysis may be more unstable and should have a more comprehensive monitoring of anti-Xa levels (See Section 5.2 Pharmacokinetic properties).Patients with severely disturbed hepatic function may need a reduction in dosage and should be monitored accordingly.If a transmural myocardial infarction occurs in patients with unstable coronary artery disease, thrombolytic treatment might be appropriate. This does not necessitate discontinuation of treatment with Fragmin, but might increase the risk of bleeding.As individual low molecular weight (mass) heparins have differing characteristics, switching to an alternative low molecular weight heparin should be avoided. The directions for use relating to each specific product must be observed as different dosages may be required.Interchangeability with other anticoagulants Dalteparin cannot be used interchangeably (unit for unit) with unfractionated heparin, Other low molecular weight heparins, or synthetic polysaccharides. Each of these medicines differ in their starting raw materials, manufacturing process, physico-chemical, biological, and clinical properties, leading to differences in biochemical identity, dosing, and possibly clinical efficacy and safety. Each of these medicines is unique and has its own instructions for use.Heparin can suppress adrenal secretion of aldosterone leading to hyperkalaemia, particularly in patients such as those with diabetes mellitus, chronic renal failure, pre-existing metabolic acidosis, a raised plasma potassium or taking potassium sparing drugs. The risk of hyperkalaemia appears to increase with duration of therapy but is usually reversible. Plasma potassium should be measured in patients at risk before starting heparin therapy and monitored regularly thereafter particularly if treatment is prolonged beyond about 7 days.In patients undergoing spinal or epidural anaesthesia, the prophylactic use of heparin may be very rarely associated with spinal haematomas resulting in prolonged or permanent paralysis. The risk is increased by use of an epidural or spinal catheter for anaesthesia, by the concomitant use of drugs (NSAIDs), platelet inhibitors or anti-coagulants and by traumatic or repeated epidural or spinal puncture.In decision-making on the interval between the last administration of Fragmin at prophylactic doses and the placement or removal of a peridural or spinal catheter for anaesthesia, the product characteristics and the patient profile should be taken into account. Readministration should be delayed until at least four hours after the surgical procedure is completed.Should a physician, as a clinical judgement, decide to administer anticoagulation in the context of peridual or spinal anaesthesia, extreme vigilance and frequent monitoring must be exercised to detect any signs and symptoms of neurologic impairment such as back pain, sensory or motor deficits (numbness and weakness in lower limbs) and bowel or bladder dysfunction. Nurses should be trained to detect such signs and symptoms. Patients should be instructed to inform immediately a nurse or a clinician if they experience any of these.If signs or symptoms of epidural or spinal haematoma are suspected, urgent diagnosis and treatment may include spinal cord decompression.There have been no adequate studies to assess the safe and effective use of Fragmin in preventing valve thrombosis in patients with prosthetic heart valves. Prophylactic doses of Fragmin are not sufficient to prevent valve thrombosis in patients with prosthetic heart valves. The use of Fragmin cannot be recommended for this purpose.Paediatric Patients: Clinical experience of treatment of children is limited. If dalteparin is used in children the anti-Xa levels should be monitored.The administration of medications containing benzyl alcohol as a preservative to premature neonates has been associated with a fatal Gasping Syndrome (see section 4.6 pregnancy and lactation).Elderly patients (especially patients aged eighty years and above) may be at an increased risk for bleeding complications within the therapeutic dosage ranges. Careful clinical monitoring is advised. | |