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Pharmacologic class: Antithrombotic
Therapeutic class: Anticoagulant
Pregnancy risk category C
Inhibits thrombus by preventing conversion of prothrombin to thrombin and fibrinogen to fibrin, preventing clot formation. Doesn't lyse existing clot, but prevents clot enlargement and extension.
Solution for flushes: 1-unit/ml, 2-units/ml, 10-units/ml, 100-units/ml syringes; 100-units/ml vials
Solution for injection: 1,000 units/ml, 10,000 units/ml, 20,000 units/ml, 40,000 units/ml in single-dose vials; 1,000 units/ml, 2,000 units/ml, 5,000 units/ml, 10,000 units/ml, 20,000 units/ml in multidose vials; 1,000 units/ml, 2,500 units/ml, 5,000 units/ml, 10,000 units/ml in unit-dose syringes
Indications and dosages
➣ Therapeutic anticoagulation
Adults: 10,000 units I.V. by intermittent bolus, then 5,000 to 10,000 units I.V. q 4 to 6 hours. Or 5,000 units by I.V. injection, then 20,000 to 40,000 units I.V. over 24 hours (about 1,000 units/hour or 15 to 18 units/kg/hour). Or 5,000 units I.V., followed by initial deep subcutaneous dose of 10,000 to 20,000 units, then 8,000 to 10,000 units q 8 hours or 15,000 to 20,000 units q 12 hours.
Children: Initially, 50 units/kg by I.V. drip, then 100 units/kg by I.V. drip q 4 hours. Or 20,000 units/m2/24 hours by continuous I.V. infusion.
➣ To prevent thromboembolism
Adults: 5,000 units subcutaneously q 8 to 12 hours (may begin 2 hours before surgery) given for 7 days or until patient is fully ambulatory
➣ To prevent blood clotting during cardiovascular surgery
Adults: At least 150 units/kg I.V. (300 units/kg if procedure less than 60 minutes; 400 units/kg if more than 60 minutes)
➣ I.V. flush
Adults and children: 10 to 100 units/ml I.V. heparin sodium solution to fill heparin lock set
• Prophylaxis of left ventricular thrombi
• Prophylaxis of cerebrovascular accident after myocardial infarction
• Hypersensitivity to drug
• Bleeding disorders
• Severe thrombocytopenia
• Patients who can't undergo regular blood coagulation tests
Use cautiously in:
• severe hepatic or renal disease, bacterial endocarditis, hypertension, brain injury, retinopathy, ulcer disease
• recent CNS or ophthalmic surgery
• immediate postpartum period
• women older than age 60
• pregnant patients.
☞ Know that I.V. heparin sodium is a high-alert drug.
• Draw baseline blood sample for clotting studies before starting drug.
☞ Use infusion pump to administer I.V. dose. Check regularly to ensure that infusion rate is correct.
• For I.V. use, give each 1,000-unit dose or single-dose injection over at least 1 minute. Give continuous infusion over 4 to 24 hours, depending on dose and volume of infusion solution.
• Draw blood for partial thromboplastin time (PTT) from opposite arm 4 hours after continuous I.V. infusion begins.
• Put note at patient's bedside to remind personnel to apply pressure dressings after withdrawing blood.
• With intermittent I.V. drug infusion, withdraw blood 30 minutes before dose, using arm without I.V. infusion.
• For subcutaneous dose, inject slowly between iliac crests in lower abdomen, deep into subcutaneous fat layer. Leave needle in place for 10 seconds before withdrawing. Don't massage area after injection. Alternate subcutaneous sites every 12 hours.
• Have protamine available as heparin agonist.
☞ Don't give I.M.
☞ Don't give heparin products containing benzyl alcohol to premature infants.
Hematologic: anemia, thrombocytopenia, bleeding, severely prolonged clotting time
Musculoskeletal: osteoporosis (with long-term use)
Skin: irritation, rash, urticaria, hematoma, ulceration, cutaneous or subcutaneous necrosis, pruritus, alopecia (with long-term use)
Other: fever, pain at injection site, hypersensitivity reactions, white clot syndrome, anaphylactoid reactions
Drug-drug. Antihistamines, digoxin, nicotine, tetracyclines: decreased anticoagulant effect of heparin
Cefamandole, cefmetazole, cefoperazone, cefotetan, plicamycin, quinidine, valproic acid, other drugs that cause hypoprothrombinemia; drugs that affect platelet function (including abciximab, aspirin, clopidogrel, dextran, dipyridamole, eptifibitide, nonsteroidal anti-inflammatory drugs, some penicillins, thrombolytics, ticlopidine, tirofiban): increased bleeding risk
Drug-diagnostic tests. Alanine aminotransferase, aspartate aminotransferase, free fatty acids, thyroxine, triiodothyronine resin: increased levels
Cholesterol, triglycerides: decreased levels
125I fibrinogen uptake: false-negative result
Prothrombin time: prolonged
Drug-herbs. Anise, arnica, chamomile, clove, dong quai, feverfew, garlic, ginger, ginseng: increased bleeding risk
Drug-behaviors. Smoking: increased bleeding risk
• Monitor infusion rate closely, even when using infusion pump.
• Evaluate patient's vital signs.
☞ Watch for signs and symptoms of anaphylactoid reaction.
☞ Assess for white clot syndrome (new thrombus formation in association with thrombocytopenia caused by irreversible platelet aggregation).
☞ Stay alert for signs and symptoms of bleeding tendency.
• Check hematocrit, PTT, and platelet count frequently.
• Monitor liver function test results.
• In long-term therapy, periodically assess stool for occult blood.
• Monitor potassium level in patients with diabetes or renal disease. (Drug may cause hyperkalemia.)
• If patient will self-administer drug, teach proper technique and emphasize need to rotate injection sites.
☞ Advise patient that nosebleed, blood in urine, or black stools may be first sign of overdose and should be reported immediately.
☞ Tell patient to immediately report other unusual bleeding or bruising.
• Urge patient to avoid activities that can cause injury. Advise him to use soft toothbrush and electric razor to avoid gum and skin injury.
• Tell patient he will undergo regular blood testing during therapy.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above.