8 Adverse Reactions). Haematocrit testing and tests for occult blood in stools should be performed periodically during heparin administration. Heparin sodium should be used with extreme caution in disease states in which there is increased danger of haemorrhage, including: • Cardiovascular - subacute bacterial endocarditis.
Severe hypertension. • Surgical - during and immediately following (a) spinal tap or spinal anaesthesia or (b) major surgery, especially involving the brain, spinal cord, or eye. • Haematologic - conditions associated with increased bleeding tendencies, such as haemophilia, thrombocytopenia, and some vascular purpuras.
• Gastrointestinal - ulcerative lesions and continuous tube drainage of the stomach or small intestine. It should be appreciated that gastrointestinal or urinary tract bleeding during anticoagulant therapy may indicate the presence of an underlying occult lesion.
8 Adverse Reactions). • Antithrombin III deficiency may be acquired or inherited. Patients with hereditary antithrombin III deficiency receiving concurrent antithrombin III therapy. 5) • Hepatic: liver disease with impaired haemostasis.
Other – menstruation Heparin-induced Thrombocytopenia (HIT) (With or Without Thrombosis) Heparin-induced Thrombocytopenia (HIT) is a serious immune-mediated reaction resulting from irreversible aggregation of platelets. HIT may progress to the development of venous and arterial thromboses, a condition referred to as HIT with thrombosis.
Thrombotic events may also be the initial presentation for HIT. These serious thromboembolic events include deep vein thrombosis, pulmonary embolism, cerebral vein thrombosis, limb ischemia, stroke, myocardial infarction, mesenteric thrombosis, renal arterial thrombosis, skin necrosis, gangrene of the extremities that may lead to amputation, and fatal outcomes.
Once HIT (with or without thrombosis) is diagnosed or strongly suspected, all heparin sources (including heparin flushes) should be discontinued and an alternative anticoagulant used. Future use of heparin, especially within 3 to 6 months following the diagnosis of HIT (with or without thrombosis), and while patients test positive for HIT antibodies, should be avoided.
Immune-mediated HIT is diagnosed based on clinical findings supplemented by laboratory tests confirming the presence of antibodies to heparin, or platelet activation induced by heparin. Platelet counts should be obtained at baseline and periodically during heparin administration.
A drop in platelet count greater than 50% from baseline is considered indicative of HIT. Platelet counts begin to fall 5 to 10 days after exposure to heparin in heparin–naive individuals, and reach a threshold by days 7 to 14. e. previous 3 months).
Thrombosis development shortly after documenting thrombocytopenia is a characteristic finding in almost half of all patients with HIT. Thrombocytopenia of any degree should be monitored closely. If the platelet count falls below 100,000/mm3 or if recurrent thrombosis develops, the administration of heparin should be promptly discontinued and alternative anticoagulants considered if patients require continued anticoagulation.
Delayed Onset of Heparin-induced Thrombocytopenia (HIT) (With or Without Thrombosis) Heparin-induced thrombocytopenia (with or without thrombosis) can occur up to several weeks after the discontinuation of heparin therapy. Patients presenting with thrombocytopenia or thrombosis after discontinuation of heparin should be evaluated for HIT (with or without thrombosis).
Thrombocytopenia Thrombocytopenia has been reported to occur in patients receiving heparin with a reported incidence of up to 30%. It can occur 2 to 20 days (average 5 to 9) following the onset of heparin therapy. Platelet counts should be obtained at baseline and periodically during heparin administration.
Mild thrombocytopenia (count greater than 100,000/mm3) may remain stable or reverse even if heparin is continued. However, thrombocytopenia of any degree should be monitored closely. If the count falls below 100,000/mm3 or if recurrent thrombosis develops (see Heparin-induced Thrombocytopenia (HIT) With or Without Thrombosis), heparin should be discontinued and, if necessary, an alternative anticoagulant administered.
Heparin Resistance Increased resistance to heparin is frequently encountered in patients with fever, thrombosis, thrombophlebitis, infections with thrombosing tendencies, myocardial infarction, cancer and postsurgical. Monitor coagulation tests closely in such patients.
It may be necessary to adjust the dose of heparin based on anti-Factor Xa levels. Hypersensitivity Hypersensitivity reactions with chills, fever and urticaria as the most usual manifestations and also asthma, rhinitis, lacrimation, and anaphylactoid reactions have been reported.
Vasospastic Reactions Vasospastic reactions may develop independent of the origin of heparin, 6 to 10 days after the initiation of the therapy and last for 4 to 6 hours. The affected limb is painful, ischemic and cyanosed. An artery to this limb may have been recently catheterized.
After repeat injections, the reaction may gradually increase to include generalized vasospasm, with cyanosis, tachypnoea, feeling of oppression and headache. Hyperkalaemia Heparin can suppress adrenal secretion of aldosterone leading to hyperkalaemia, particularly in patients 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 upon discontinuation of heparin. Plasma potassium should be measured in patients at risk of hyperkalaemia […]