Enoxaparin: Action Uses Administration Dosage Nursing Considerations by NJE

Uses of Enoxaparin

DVT prophylaxis following hip or knee replacement surgery, abdominal surgery, or pts with severely restricted mobility during acute illness. Treatment of acute coronary syndrome (ACS): unstable angina, non–Q-wave MI, acute ST-segment elevation MI (STEMI). Treatment of DVT with or without pulmonary embolism (PE) (inpatient); without PE (outpatient). 

OFF-LABEL: DVT prophylaxis following moderate-risk general surgery, gynecologic surgery; management of venous thromboembolism (VTE) during pregnancy. Bariatric surgery, mechanical heart valve to bridge anticoagulation, percutaneous coronary intervention (PCI) adjunctive therapy.

Action of Enoxaparin

Potentiates action of antithrombin III, inactivates coagulation factor Xa.

Therapeutic Effect: Produces anticoagulation. Does not significantly influence PT, aPTT.

CLASSIFICATION  of Enoxaparin

PHARMACOTHERAPEUTIC: Low molecular weight heparin.

CLINICAL: Anticoagulant.

BLACK BOX ALERT ■ Epidural or spinal anesthesia greatly increases the potential for spinal or epidural hematoma, subsequent long-term or permanent paralysis.

Precautions of Enoxaparin

Contraindications: Hypersensitivity to enoxaparin. Active major bleeding, concurrent heparin therapy, hypersensitivity to heparin, pork products, thrombocytopenia associated with positive in vitro test for antiplatelet antibodies. Not for IM use.

Cautions: Conditions with increased risk of hemorrhage, platelet defects, renal impairment (renal failure), elderly, uncontrolled arterial hypertension, history of recent GI ulceration or hemorrhage. When neuraxial anesthesia (epidural or spinal anesthesia) or spinal puncture is used, pts anticoagulated or scheduled to be anticoagulated with enoxaparin for prevention of thromboembolic complications are at risk for developing an epidural or spinal hematoma that can result in long-term or permanent paralysis. Bacterial endocarditis, hemorrhagic stroke, history of heparin-induced thrombocytopenia (HIT), severe hepatic disease.

Pharmacokinetics  of Enoxaparin

Well absorbed after subcutaneous administration. Excreted primarily in the urine.Not removed by hemodialysis. Half-life: 4.5–7 hrs. 

Lifespan considerations

Pregnancy/Lactation: Use with caution, particularly during the third trimester, immediate postpartum period (increased risk of maternal hemorrhage). Unknown if distributed in breast milk. Pregnant women with mechanical heartvalves (and their fetuses) may have an increased risk of bleeding.

Children: Safety and efficacy not established.

Elderly: Maybe more susceptible to bleeding.

Interactions

DRUG: Antiplatelet agents (e.g., clopidogrel), aspirin, NSAIDs (e.g., ibuprofen, ketorolac, naproxen), thrombolytics (e.g., tPA) may increase the risk of bleeding.

HERBAL: Cat’s claw, dong Quai, evening primrose, feverfew, garlic, ginger, ginkgo, ginseng may increase antiplatelet action.

FOOD: None known.

LAB VALUES: Increases serum alkaline phosphatase, ALT, AST. May decrease Hgb, Hct, platelets, RBCs.

Availability (Rx)

Injection Solution: 30 mg/0.3 mL, 40 mg/0.4 mL, 60 mg/0.6 mL, 80 mg/0.8 mL, 100 mg/mL, 120 mg/0.8 mL, 150 mg/mL in prefilled syringes. 

Administration/handling of Enoxaparin

Do not mix with other injections, infusions. Do not give IM.

Subcutaneous 

Preparation

• Visually inspect for particulate matter or discoloration. The solution should appear clear, colorless to pale yellow in color. Do not use if the solution is cloudy, discolored, or if visible particles are observed.

Administration 

• Flick syringe so that the air bubble rises toward the plunger.

• Insert needle subcutaneously into abdomen or outer thigh and inject solution (including air bubble).

• Do not inject into areas of active skin disease or injury such as sunburns, skin rashes, inflammation, skin infections, or active psoriasis.

• Rotate injection sites.

Storage

• Store at room temperature.

Indications/routes/dosage of Enoxaparin

Prevention of Deep Vein Thrombosis (DVT) After Hip and Knee Surgery.

SQ: ADULTS, ELDERLY: 30 mg twice daily, generally for 7–10 days, with initial dose given within 12–24 hrs following surgery. Hip surgery: An initial dose of 40 mg, given 9–15 hrs before surgery, may be considered for some pts. Following hip surgery, recommend continuing 40 mg once daily for 3 wks (if 40 mg dose was initially given).

Prevention of DVT After Abdominal Surgery

SQ: ADULTS, ELDERLY: 40 mg/day for 7–10 days, with initial dose given 2 hrs prior to surgery.

Prevention of DVT After Bariatric Surgery

BMI 50 or less (kg/m2) 40 mg q12h. BMI is greater than 50 kg/m2: 60 mg q12h.

Prevention of Long-Term DVT in Nonsurgical Acute Illness

SQ: ADULTS, ELDERLY: 40 mg once daily; continue until the risk of DVT has diminished (usually 6–11 days). 

Prevention of Ischemic Complications of Unstable Angina, Non–Q-Wave MI (with Oral Aspirin Therapy)

SQ: ADULTS, ELDERLY: 1 mg/kg q12h (with oral aspirin).

STEMI 

SQ: ADULTS YOUNGER THAN 75 YRS: 30 mg IV once plus 1 mg/kg q12h (maximum: 100 mg first 2 doses only). ADULTS 75 YRS OR OLDER: 0.75mg/kg (maximum: 75 mg first 2 doses only) q12h.

Acute DVT

SQ: ADULTS, ELDERLY: (Inpatient): 1 mg/kg q12h or 1.5 mg/kg once daily. (Outpatient): 1 mg/kg q12h. 

Usual Pediatric Dosage 

SQ: CHILDREN 2 MOS AND OLDER: 0.5 mg/kg q12h (prophylaxis); 1 mg/kg q12h (treatment).

NEONATES, INFANTS YOUNGER THAN 2 MOS:0.75/mg/kg/dose q12h (prophylaxis); 1.5 mg/kg/dose q12h (treatment). 

Dosage in Renal Impairment 

Elimination is decreased when CrCl is less than 30 mL/min. Monitor and adjust dosage as necessary.

Dosage in Hepatic Impairment 

Use caution. 

Side effects of Enoxaparin

Occasional (4%–1%): Injection site hematoma, nausea, peripheral edema.

Adverse effects/toxic reactions

May lead to bleeding complications ranging from local ecchymoses to major hemorrhage. May cause heparin-induced thrombocytopenia (HIT). Antidote: IV injection of protamine sulfate (1% solution) equal to dose of enoxaparin injected.1 mg protamine sulfate neutralizes 1 mg enoxaparin. One additional dose of 0.5 mg protamine sulfate per 1 mg enoxaparin may be given if aPTT tested 2–4 hrs after the first injection remains prolonged. 

Nursing considerations of Enoxaparin

Obtain baseline CBC. Note platelet count. Question medical history as listed in Precautions. Ensure that pt has not received spinal anesthesia, spinal procedures. Assess for active bleeding. Assess pt’s willingness to self-inject medication.Assess the potential risk of bleeding.

Intervention/evaluation

Periodically monitor CBC, platelet count, stool for occult blood (no need for daily monitoring in pts with normal presurgical coagulation parameters). A decrease in the platelet count of more than 50% from baseline may indicate heparin-induced thrombocytopenia. Ensure active hemostasis of puncture site following PCI. Assess for any sign of bleeding (bleeding at the surgical site, hematuria, blood in stool, bleeding from gums, petechiae, bruising, bleeding from injection sites).

Patient/family teaching 

• Usual length of therapy is 7–10 days.

• A health care provider will show you how to properly prepare and inject your medication. You must demonstrate correct preparation and injection techniques before using medication at home.

• Do not discontinue current blood-thinning regimen or take any newly prescribed medications unless approved by the prescriber who originally started treatment.

• Suddenly stopping therapy may increase the risk of blood clots or stroke.

 • Report bleeding of any kind (bloody urine, stool; nosebleeds; increased menstrual bleeding). If bleeding occurs, it may take longer to stop bleeding.

• Immediately report signs of stroke (confusion, headache, numbness, one-sided weakness, trouble speaking, loss of vision).

• Minor blunt force trauma to the head, chest, or abdomen can be life-threatening.

• Do not take aspirin, herbal supplements, OTC nonsteroidal anti-inflammatories (may increase risk of bleeding).

• Consult physician before any surgery/dental work

.• Use an electric razor, soft toothbrush to prevent bleeding.

Reference Saunders pharmacology Nursing