enoxaparin sodium

enoxaparin sodium Warning - High-alert drug!

Clexane (UK), Lovenox 3.

Pharmacologic class: Low-molecular-weight heparin

Therapeutic class: Anticoagulant

Pregnancy risk category B

FDA Boxed Warning

• During epidural or spinal anesthesia or puncture, patients receiving drug or scheduled to receive it for thromboprophylaxis are at risk for epidural or spinal hematoma, which can lead to long-term or permanent paralysis. Risk increases with use of indwelling epidural catheter for analgesia administration and with concurrent use of drugs affecting hemostasis (such as nonsteroidal anti-inflammatory drugs [NSAIDs], platelet inhibitors, and other anticoagulants). Risk also rises with traumatic or repeated epidural or spinal puncture. Before neuraxial intervention, physician should weigh drug's potential benefit against risk.
• Monitor patient frequently for signs and symptoms of neurologic impairment.

Action

Inhibits thrombus and clot formation by blocking factor Xa and factor IIa. This inhibition accelerates formation of antithrombin III-thrombin complex (a coagulation inhibitor), thereby deactivating thrombin and preventing conversion of fibrinogen to fibrin.

Availability

Solution for injection: 30 mg/0.3 ml, 40 mg/0.4 ml, 60 mg/0.6 ml, 80 mg/0.8 ml, 100 mg/1 ml (all in prefilled syringes); 300 mg/3 ml (in multidose vials)

⊘Indications and dosages

➣ Prevention of pulmonary embolism and deep-vein thrombosis (DVT) after abdominal surgery

Adults: 40 mg subcutaneously 2 hours before surgery, repeated 24 hours after initial dose (provided hemostasis has been established) and continued once daily for 7 to 10 days until risk of DVT has diminished

➣ Prevention of pulmonary embolism and DVT after hip or knee replacement surgery

Adults: 30 mg subcutaneously 12 to 24 hours after surgery (provided hemostasis has been established), repeated q 12 hours for 7 to 10 days until risk of DVT has diminished. Alternatively, hip-replacement patient may receive 40 mg subcutaneously 12 hours before surgery and then once daily for 3 weeks, for a total of 4 weeks of therapy.

➣ Prevention of ischemic complications of unstable angina or non-Q-wave myocardial infarction

Adults: 1 mg/kg subcutaneously q 12 hours, given with aspirin 100 to 325 mg P.O. once daily until patient is clinically stable

➣ Hospitalized patients with acute DVT with or without pulmonary embolism (PE) (given with warfarin sodium)

Adults: 1 mg/kg subcutaneously q 12 hours or 1.5 mg/kg subcutaneously once daily for 5 to 7 days until therapeutic effect is established. Warfarin therapy usually begins within 72 hours of enoxaparin injection.

➣ Outpatients with acute DVT without PE (given with warfarin sodium)

Adults: 1 mg/kg subcutaneously q 12 hours for 5 to 7 days until therapeutic effect is established. Warfarin therapy usually begins within 72 hours of enoxaparin injection.

Dosage adjustment

• Patients weighing less than 45 kg (99 lb)
• Creatinine clearance below 30 ml/minute

Off-label uses

• Prevention of clots associated with hemodialysis
• Prevention of thrombosis during pregnancy

Contraindications

• Hypersensitivity to drug, heparin, sulfites, benzyl alcohol, or pork products
• Thrombocytopenia
• Active major bleeding

Precautions

Use cautiously in:
• severe hepatic or renal disease, retinopathy (hypertensive or diabetic), uncontrolled hypertension, hemorrhagic stroke, bacterial endocarditis, GI bleeding or other bleeding disorders
• recent history of ulcer disease, history of congenital or acquired bleeding disorder, history of thrombocytopenia related to heparin use
• recent CNS surgery
• pregnant or breastfeeding patients
• children.

Administration

☞ Be aware that enoxaparin is a high-alert drug.
• Use tuberculin syringe with multidose vial to ensure accurate dosage.
• Don't expel air bubble from syringe before administering.
• Inject drug deep subcutaneously with patient in supine position. Alternate left and right anterolateral and posterolateral abdominal wall sites.
• Don't rub injection site.
☞ Don't give by I.M. or I.V. route.

Route	Onset	Peak	Duration
Subcut.	Unknown	3-5 hr	24 hr

Adverse reactions

CNS: dizziness, headache, insomnia, confusion, cerebrovascular accident

CV: edema, chest pain, atrial fibrillation, heart failure

GI: nausea, vomiting, constipation

GU: urinary retention

Hematologic: anemia, bleeding tendency, thrombocytopenia, hemorrhage

Metabolic: hyperkalemia

Skin: bruising, pruritus, rash, urticaria

Other: fever; pain, irritation, or erythema at injection site

Interactions

Drug-drug. Warfarin, other drugs that affect platelet function (including abciximab, aspirin, clopidogrel, dextran, dipyridamole, eptifibatide, NSAIDs, some penicillins, ticlopidine, tirofiban): increased risk of bleeding

Drug-diagnostic tests. Hepatic enzymes: reversible increases

Hemoglobin, platelets: decreased levels

Drug-herbs. Anise, arnica, chamomile, clove, feverfew, garlic, ginger, ginkgo, ginseng: increased risk of bleeding

Patient monitoring

• Monitor CBC and platelet counts. Watch for signs and symptoms of bleeding or bruising.
• Monitor fluid intake and output. Watch for fluid retention and edema.

Patient teaching

• If patient will self-administer drug, teach proper injection technique.
☞ Instruct patient to promptly report irregular heart beat, unusual bleeding or bruising, rash, or hives.
• Teach patient safety measures to avoid bruising or bleeding.
• Advise patient to weigh himself regularly and to report gains.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and herbs mentioned above.