Dosing and uses of Lovenox (enoxaparin)
Adult dosage forms and strengths
multidose viaL
- 100mg/mL (3mL vial)
prefilled syringe
- 30mg/0.3mL
- 40mg/0.4mL
- 60mg/0.6mL
- 80mg/0.8mL
- 100mg/mL
- 120mg/0.8mL
- 150mg/mL
Deep Vein Thrombosis (Prophylaxis)
Prevent the occurrence of pulmonary embolism in patients at risk for thromboembolic complications who are undergoing abdominal surgery or hip or knee replacement surgery, as well as in medical patients with severely restricted mobility during acute illness
Abdominal surgery
- 40 mg SC qDay; initiate 2 hr preoperatively
Knee or hip replacement surgery
- 30 mg SC q12hr; initiate therapy 12-24 hr postoperatively and continued for 10 days or up to 35 days postoperatively or until risk of DVT has been significantly reduced or patient is on anticoagulant therapy
- For hip replacement surgery, may consider administering 40 mg SC qDay, initiated 9-15 hr preoperatively and continued for 10 days or up to 35 days postoperatively or until risk of DVT has been significantly reduced or patient is on anticoagulant therapy
Medical patients with restricted mobility
- 40 mg SC qDay; continue until risk of DVT has been significantly (6-11 days) reduced or patient is on anticoagulant therapy
Dosing considerations
- Abdominal surgery: Duration of administration is 7-10 days; up to 12 days has been administered in clinical trials or until risk of DVT has diminished
- Knee or hip replacement surgery: Duration of administration is 7-10 days; up to 14 days has been administered in clinical trials or until risk of DVT has diminished
- Medical patients with restricted mobility: Duration of administration is 6-11 days; up to 14 days has been administered in clinical trials
Deep Vein Thrombosis (Treatment)
Inpatient treatment
- Acute DVT with or without PE, when administered in conjunction with warfarin sodium
- 1 mg/kg SC q12hr, OR 1.5 mg/kg SC qDay (administer at same time each day)
Outpatient treatment
- Acute DVT without PE, when administered in conjunction with warfarin sodium
- 1 mg/kg SC q12hr
Dosing considerations
- In inpatient and outpatient treatments, initiate warfarin therapy within 72 hours of starting enoxaparin
- Continue enoxaparin for a minimum of 5 days and until a therapeutic oral anticoagulant effect has been achieved (INR 2.0-3.0)
- Average duration of administration is 7 days; up to 17 days has been administered in clinical trials
Unstable Angina & Non-Q-Wave MI
Prophylaxis of ischemic complications of unstable angina and non-Q-wave myocardial infarction, when concurrently administered with aspirin
1 mg/kg SC q12hr
Regimen includes aspirin (100-325 mg/day PO)
Dosing considerations
- Administer for at least 2 days and then continue until clinical stabilization
- Usual duration of treatment is 2-8 days; up to 12.5 days has been administered in clinical trials
Acute STEMI
Reduce the rate of the combined endpoint of recurrent myocardial infarction or death in patients with acute ST-segment elevation myocardial infarction (STEMI) receiving thrombolysis and being managed medically or with percutaneous coronary intervention (PCI)
All patients should receive aspirin as soon as they are identified as having STEMI and should be maintained with 75-325 mg PO qDay unless contraindicated
<75 years
- Loading dose: 30 mg IV bolus once plus 1 mg/kg SC once; not to exceed 100 mg cumulative loading dose
- Maintenance: 1 mg/kg SC q12hr
>75 years
- No IV bolus
- 0.75 mg/kg SC q12hr
- Not to exceed 75 mg/dose for first 2 doses only, followed by 0.75 mg/kg for remaining doses
With PCI
- If last enoxaparin was given <8 hr before balloon inflation, no additional dosing is needed
- If last enoxaparin was given 8-12 hr before balloon inflation, an IV bolus of 0.3 mg/kg should be administered
- If PCI occurs >12 hr after last SC dose; use established anticoagulation therapy (full-dose unfractionated heparin or LMWH
- Patient that has not received prior anticoagulant therapy: 0.5-0.75 mg/kg bolus dose
Dosing considerations
- Administered concurrently with aspirin
- In conjunction with thrombolytic: Administer enoxaparin between 15 minutes before and 30 minutes after initiating fibrinolytic therapy; optimal treatment duration of enoxaparin is 8 days or until hospital discharge (whichever comes first)
Dosing Modifications
Renal impairment
- Severe (CrCl <30 mL/min): Dosage reductions required
- Prophylaxis in abdominal surgery: 30 mg SC qDay
- Prophylaxis in hip or knee replacement surgery: 30 mg SC qDay
- Prophylaxis in medical patients with restricted mobility: 30 mg SC qDay
- DVT treatment (inpatient or outpatient) coadministered with warfarin: 1 mg/kg SC qDay
- Non-Q-wave myocardial infarction: 1 mg/kg SC qDay
- Treatment of acute STEMI (<75 years): 30 mg IV single bolus plus 1 mg/kg SC, THEN 1 mg/kg SC qDay
- Treatment of acute STEMI (>75 years): No initial bolus; maintenance of 1 mg/kg SC qDay
Administration
Low body weight (<45 kg for women or <57 kg for men): Increased exposure has been observed with prophylactic (non-weight adjusted) dosage; carefully monitor for sign/symptoms of bleeding
Administer deep SC alternating right and left anterior and posterior abdominal walls into skin fold held between thumb and forefinger
Use of tuberculin syringe (or equivalent) is recommended to assure appropriate measurement of dose
For IV administration, may administer in IV line with 0.9% NaCl or D5W
Pediatric dosage forms and strengths
multidose viaL
- 100mg/3mL
prefilled syringe
- 30mg/0.3mL
- 40mg/0.4mL
- 60mg/0.6mL
- 80mg/0.8mL
- 100mg/mL
- 120mg/0.8mL
- 150mg/mL
Deep Vein Thrombosis (Off-label)
Prophylaxis
- <2 months: 0.75 mg/kg SC q12hr
- ≥2 months: 0.5 mg/kg SC q12hr
Treatment
- <2 months: 1.5 mg/kg SC q12hr
- ≥2 months: 1 mg/kg SC q12hr
Dose Titration for Pediatric Dosing Based on Anti-Factor Xa Concentrations
- <0.35 units/mL: Increase dose by 25%; administer next dose at scheduled time; repeat anti-factor Xa level 4 hr after next dose
- 0.35-0.46 units/mL: Increase dose by 10%; administer next dose at scheduled time; repeat anti-factor Xa level 4 hr after next dose
- 0.5 - 1 units/mL: Dose adjustment not necessary; administer next dose at scheduled time; repeat anti-factor Xa level every other day
- 1.1-1.5 units/mL: Decrease dose by 20%; administer next dose at scheduled time; repeat anti-factor Xa level 4 hr after next dose
- 1.6-2 units/mL: Decrease dose by 30%; delay next dose 3 hr; repeat anti-factor Xa level 4 hr after next dose
- >2 units/mL: Decrease dose by 40%; delay next dose until anti-factor Xa <0.5 units/mL; repeat anti-factor Xa level before next dose and every 12 hr until anti-factor Xa <0.5 units/mL
Dosing considerations
- Multidose vial contains benzyl alcohol, which is associated with gasping syndrome in premature infants
Geriatric dosage forms and strengths
Increased risk of bleeding with doses of 1.5 mg/kg/day or 1 mg/kg q12hr
Dosing considerations
Risk of serious adverse reactions increases in the elderly
Body weight <45 kg may require dose adjustment
Lovenox (enoxaparin) adverse (side) effects
1-10%
Hemorrhage (1-4%)
Elevation of serum aminotransferases (6%)
Fever (5-8%)
Local site reactions (2-5%)
Thrombocytopenia (3%)
Nausea (3%)
Anemia (2%)
Ecchymosis (3%)
<1%
Atrial fibrillation
Heart failure
Pulmonary edema
Pneumonia
Postmarketing Reports
Reports of epidural or spinal hematoma formation when coadministered with spinal/epidural anesthesia or spinal puncture
Local reactions at the injection site (eg, nodules, inflammation, oozing), systemic allergic reactions (eg, pruritus, urticaria, anaphylactic/anaphylactoid reactions including shock), vesiculobullous rash, rare cases of hypersensitivity cutaneous vasculitis, purpura, skin necrosis (occurring at either the injection site or distant from the injection site), thrombocytosis, and thrombocytopenia with thrombosis
Hyperkalemia
Cases of headache, hemorrhagic anemia, eosinophilia, alopecia, hepatocellular and cholestatic liver injury reported
Osteoporosis following long-term therapy
Warnings
Black box warnings
Epidural or spinal hematomas may occur in patients anticoagulated with low-molecular-weight heparin (LMWH) or heparinoids who receive neuraxial (epidural/spinal) anesthesia or spinal puncture
These hematomas may result in long-term or permanent paralysis
Patients should be frequently monitored for signs and symptoms of neurologic impairment (eg, tingling, numbness, muscular weakness)
If neurologic compromise is noted, urgent treatment is necessary
Physicians should consider the benefits versus risk before neuraxial intervention in patients anticoagulated or to be anticoagulated for thromboprophylaxis
Factors increasing risk of epidural or spinal hematomas
- Indwelling epidural catheters
- Concomitant use of other drugs that affect hemostasis (eg, NSAIDs, platelet inhibitors, other anticoagulants)
- History of traumatic or repeated epidural or spinal punctures
- History of spinal deformity or spinal surgery
Appropriate timing of enoxaparin dosing in relation to catheter placement or removaL
- Optimal timing between the administration of enoxaparin and neuraxial procedures is not known
- Placement or removal of a spinal catheter should be delayed for at least 12 hr after administration of prophylactic doses (eg, doses used for DVT prevention)
- Longer delays (24 hr) are appropriate to consider for patients receiving higher therapeutic doses (eg, enoxaparin 1 mg/kg BID or 1.5 mg/kg qDay)
- A post procedure dose of enoxaparin should usually be given no sooner than 4 hr after catheter removal
- In all cases, a benefit-risk assessment should consider both the risk for thrombosis and the risk for bleeding in the context of the procedure and patient risk factors
Contraindications
Active major bleeding, thrombocytopenia with antiplatelet antibody in presence of enoxaparin or heparin
Hypersensitivity to enoxaparin, heparin, pork products, or other ingredients
Cautions
Epidural or spinal hemorrhage and subsequent hematomas reported with the use of enoxaparin and epidural or spinal anesthesia/analgesia or spinal puncture procedures, resulting in long-term or permanent paralysis (see Black box warnings)
Bleeding may occur; monitor patients with risk factors including congenital or acquired bleeding disorders, bacterial endocarditis, severe uncontrolled hypertension, hemorrhagic stroke, used shortly after brain, spinal, or ophthalmic surgery in patients treated concomitantly with platelet inhibitors or history of heparin induced thrombocytopenia, severe liver disease, diabetic retinopathy, patients undergoing invasive procedures, active ulcerative or angiodysplastic diseases, recent GI bleeding or ulceration
To minimize risk of bleeding following PCI, achieve hemostasis, at puncture site after PCI; sheath can be removed immediately if closure device used; if manual compression used remove sheath 6 hr after last IV/SC dose of enoxaparin; additional doses not recommended until 6-8 hr after sheath removal; observe for signs of bleeding/hematoma formation
Multidose formulation contains benzyl alcohol preservative, linked to fatal "gasping syndrome" in premature neonates
Monitor for hyperkalemia (possibly from aldosterone suppression); mainly a concern among patients with risk factors including renal dysfunction, concomitant use of potassium sparing diuretics or potassium supplements
Enoxaparin-induced thrombocytopenia and thrombosis reported; use extreme caution or avoid in patients with history heparin induced thrombocytopenia (HIT), especially if administered within 100 days of HIT episode; monitor platelet count closely; discontinue therapy and consider alternate treatment if platelets are <100,000/mm³ and/or thrombosis develops
Not for long-term thrombocytopenia in patients with prosthetic heart valves
Not for IM administration
Use caution in patients with renal impairment
Safety and efficacy not established in obese patients (>30 kg/m²)
Risk of bleeding may increase in women <45 kg and men <57 kg
Not for use interchangeably (unit for unit) with heparin or any LMWHs
Pregnancy and lactation
Pregnancy category: B
Lactation: Excretion in milk unknown; not recommended
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Lovenox (enoxaparin)
Mechanism of action
LMWH; antithrombotic that inhibits factor Xa by increasing inhibition rate of clotting proteases that are activated by antithrombin III
Generally does not increase PT or PTt
Absorption
Bioavailability: 92%
Onset: 3-5 hr (peak effect)
Duration: 12 hr (40 mg)
AUC: 14.26 hr·U/mL
Distribution
Vd: 4.3 L
Metabolism
Metabolized by liver via desulfation and/or depolymerization to lower molecular weight species
Elimination
Half-life: 4.5 hr (single dose based on anti-Xa activity); 7 hr (repeated dosing)
Total body clearance: 26 mL/min
Excretion: Urine (40%)
