Indications/Uses
Prophylaxis and treatment of thromboembolic disorders, catheter patency, also used in extracorporeal circulation procedure involving heart lung and renal dialysis machines.
Clinical Pharmacology - Heparin acts on coagulation factors in both the intrinsic and extrinsic coagulation pathways. Low concentrations of heparin when combined with antithrombin III inactivate factor Xa and prevent the conversion of prothrombin to thrombin. In higher doses, heparin inactivates thrombin, blocks the conversion of fibrinogen to fibrin and when combined with antithrombin III inactivates factors IX, X, XI, XII. By inhibiting the activation of factor XIII (fibrin stabilizing factor), heparin also prevents the formation of stable fibrin clots. While heparin will inhibit the reactions that lead to clotting, it does not significantly change the concentrations of clotting factors. Heparin does not lyse clots, but can prevent the growth of existing clots.
Doses & Administrations:
Parenteral (I/V infusion, intermittent I/V, deep S.C). Adult: Initially 12,500 units followed by continuous infusion of 20,000-40,000 units over 24 hours or 5000- 10,000 units by I/V injection every 4-6 hours. Prophylaxis of deep-vein thrombosis: 5000 units 2 hours before surgery, then every 8-12 hours until patients is ambulatory. Pediatric : 50 units/kg initially as a loading dose. Maintenance: 50-100 units/kg/dose every 4 hour I/V. note: Each mg of Heparin Sodium intended for parenteral use contain=150IU of Heparin
Pharmacokinetics - Heparin is not absorbed by the gut if administered orally and must be given parenterally to be effective. Anticoagulant activity begins immediately after direct IV bolus injection, but may take up to one hour after deep SQ injection. When heparin is given by continuous IV infusion, an initial bolus must be administered for full anticoagulant activity to begin.
Heparin is extensively protein bound, primarily to fibrinogen, low-density lipoproteins and globulins. It does not appreciably cross the placenta or enter milk.
Heparin’s metabolic fate is not completely understood. The drug is apparently partially metabolized by the liver and also inactivated by the reticuloendothelial system. Serum half-lives in humans average 1-2 hours.
Contra Indications:
Hypersensitivity to heparin, severe thrombocytopenia, uncontrollable bleeding.
Precautions:
Severe renal or hepatic disease, hemophilia, thrombocytopenia, subacute bacterial endocarditis, severe hypertension, menstruation, threatened abortion, major surgery.
Pregnancy Status:
Category "C"
Renal Failure Doses:
No dosage adjustment of heparin is necessary in patients with renal failure.
Lactation Status:
Safe Interactions:
NSAID, warfarin, dextran, ACTH, digitalis, nicotine insulin.
Adverse Effects:
Hemorrhage, mild pain , local-irritation, hematoma at site of injection, chill, fever, urticaria, headache, nausea, vomiting, shock, thrombocytopenia.
Anda baru saja membaca artikel yang berkategori Heparin Anticoagulation /
Heparin Disorders /
Heparin Prophylaxis /
Heparin Treatment
dengan judul Heparin Anticoagulation Prophylaxis and Treatment of Thromboembolic Disorders. Anda bisa bookmark halaman ini dengan URL https://medipub.blogspot.com/2011/08/heparin-anticoagulation-prophylaxis-and_01.html. Terima kasih!
Ditulis oleh:
Unknown - Monday, 1 August 2011
