Abdominal Surgery
The recommended dose of Enoxaparin Sodium Injection is 40 mg by subcutaneous injection once a day (with the initial dose given 2 hours prior to surgery) in patients undergoing abdominal surgery who are at risk for thromboembolic complications. The usual duration of administration is 7 to 10 days [see Clinical Studies (14.1)].
Hip or Knee Replacement Surgery
The recommended dose of Enoxaparin Sodium Injection is 30 mg every 12 hours administered by subcutaneous injection in patients undergoing hip or knee replacement surgery. Administer the initial dose 12 to 24 hours after surgery, provided that hemostasis has been established. The usual duration of administration is 7 to 10 days [see Clinical Studies (14.2)].
A dose of Enoxaparin Sodium Injection of 40 mg once a day subcutaneously may be considered for hip replacement surgery for up to 3 weeks. Administer the initial dose 12 (±3) hours prior to surgery.
Medical Patients During Acute Illness
The recommended dose of Enoxaparin Sodium Injection is 40 mg once a day administered by subcutaneous injection for medical patients at risk for thromboembolic complications due to severely restricted mobility during acute illness. The usual duration of administration is 6 to 11 days [see Clinical Studies (14.3)].
Treatment of Deep Vein Thrombosis with or without Pulmonary Embolism
The recommended dose of Enoxaparin Sodium Injection is 1 mg/kg every 12 hours administered subcutaneously in patients with acute deep vein thrombosis without pulmonary embolism, who can be treated at home in an outpatient setting.
The recommended dose of Enoxaparin Sodium Injection is 1 mg/kg every 12 hours administered subcutaneously or 1.5 mg/kg once a day administered subcutaneously at the same time every day for inpatient (hospital) treatment of patients with acute deep vein thrombosis with pulmonary embolism or patients with acute deep vein thrombosis without pulmonary embolism (who are not candidates for outpatient treatment).
In both outpatient and inpatient (hospital) treatments, initiate warfarin sodium therapy when appropriate (usually within 72 hours of Enoxaparin Sodium Injection). Continue Enoxaparin Sodium Injection for a minimum of 5 days and until a therapeutic oral anticoagulant effect has been achieved (International Normalization Ratio 2 to 3). The average duration of administration is 7 days [see Clinical Studies (14.4)].
Unstable Angina and Non–Q-Wave Myocardial Infarction
The recommended dose of Enoxaparin Sodium Injection is 1 mg/kg administered subcutaneously every 12 hours in conjunction with oral aspirin therapy (100 to 325 mg once daily) in patients with unstable angina or non–Q-wave myocardial infarction. Treat with Enoxaparin Sodium Injection for a minimum of 2 days and continue until clinical stabilization. The usual duration of treatment is 2 to 8 days [see Warnings and Precautions (5.2) and Clinical Studies (14.5)].
Treatment of Acute ST-Segment Elevation Myocardial Infarction
The recommended dose of Enoxaparin Sodium Injection is a single intravenous bolus of 30 mg plus a 1 mg/kg subcutaneous dose followed by 1 mg/kg administered subcutaneously every 12 hours (maximum 100 mg for the first two doses only, followed by 1 mg/kg dosing for the remaining doses) in patients with acute ST-segment elevation myocardial infarction. Reduce the dosage in patients ≥75 years of age [see Dosage and Administration (2.4)]. Unless contraindicated, administer aspirin to all patients as soon as they are identified as having STEMI and continue dosing with 75 to 325 mg once daily.
When administered in conjunction with a thrombolytic (fibrin specific or non–fibrin specific), administer Enoxaparin Sodium Injection between 15 minutes before and 30 minutes after the start of fibrinolytic therapy. The usual duration of Enoxaparin Sodium Injection therapy is 8 days or until hospital discharge.
For patients managed with percutaneous coronary intervention (PCI), if the last Enoxaparin Sodium Injection subcutaneous administration was given less than 8 hours before balloon inflation, no additional dosing is needed. If the last Enoxaparin Sodium Injection subcutaneous administration was given more than 8 hours before balloon inflation, administer an intravenous bolus of 0.3 mg/kg of Enoxaparin Sodium Injection [see Warnings and Precautions (5.2)].
Hemorrhage
The following rates of major bleeding events have been reported during clinical trials with
Enoxaparin Sodium Injection (see Tables 2 to 7).
| Table 2 Major Bleeding Episodes Following Abdominal and Colorectal Surgery Bleeding complications were considered major: (1) if the hemorrhage caused a significant clinical event, or (2) if accompanied by a hemoglobin decrease 2 g/dL or transfusion of 2 or more units of blood products. Retroperitoneal, intraocular, and intracranial hemorrhages were always considered major. |
|---|
| Indications | Dosing Regimen |
|---|
| Enoxaparin Sodium Injection | Heparin |
| 40 mg daily subcutaneously | 5000 U q8h subcutaneously |
| Abdominal Surgery | n=555 | n=560 |
| 23 (4%) | 16 (3%) |
| Colorectal Surgery | n=673 | n=674 |
| 28 (4%) | 21 (3%) |
Table 3 Major Bleeding Episodes Following Hip or Knee Replacement SurgeryBleeding complications were considered major: (1) if the hemorrhage caused a significant clinical event, or (2) if accompanied by a hemoglobin decrease 2 g/dL or transfusion of 2 or more units of blood products. Retroperitoneal and intracranial hemorrhages were always considered major. In the knee replacement surgery trials, intraocular hemorrhages were also considered major hemorrhages.
| Dosing Regimen |
|---|
| Indications | Enoxaparin Sodium Injection 40 mg daily subcutaneously | Enoxaparin Sodium Injection 30 mg q12h subcutaneously | Heparin 15,000 U/24h subcutaneously |
|---|
| Hip Replacement Surgery without Extended Prophylaxis Enoxaparin Sodium Injection 30 mg every 12 hours subcutaneously initiated 12 to 24 hours after surgery and continued for up to 14 days after surgery. | | n = 786 31 (4%) | n = 541 32 (6%) |
| Hip Replacement Surgery with Extended Prophylaxis | | | |
| Peri-operative Period Enoxaparin Sodium Injection 40 mg subcutaneously once a day initiated up to 12 hours prior to surgery and continued for up to 7 days after surgery. | n = 288 | | |
| 4 (2%) | | |
| Extended Prophylaxis Period Enoxaparin Sodium Injection 40 mg subcutaneously once a day for up to 21 days after discharge. | n = 221 0 (0%) | | |
| Knee Replacement Surgery without Extended Prophylaxis | | n = 294 3 (1%) | n = 225 3 (1%) |
NOTE: At no time point were the 40 mg once a day pre-operative and the 30 mg every 12 hours postoperative hip replacement surgery prophylactic regimens compared in clinical trials. Injection site hematomas during the extended prophylaxis period after hip replacement surgery occurred in 9% of the Lovenox patients versus 1.8% of the placebo patients.
Table 4 Major Bleeding Episodes in Medical Patients with Severely Restricted Mobility During Acute IllnessBleeding complications were considered major: (1) if the hemorrhage caused a significant clinical event, (2) if the hemorrhage caused a decrease in hemoglobin of 2 g/dL or transfusion of 2 or more units of blood products. Retroperitoneal and intracranial hemorrhages were always considered major although none were reported during the trial.
| Dosing Regimen |
|---|
| Indications | Enoxaparin Sodium Injection The rates represent major bleeding on study medication up to 24 hours after last dose. | Enoxaparin Sodium Injection† | Placebo† |
|---|
| 20 mg daily subcutaneously | 40 mg daily subcutaneously | |
| Medical Patients During Acute Illness | n = 351 1 (<1%) | n = 360 3 (<1%) | n = 362 2 (<1%) |
Table 5 Major Bleeding Episodes in Deep Vein Thrombosis with or without Pulmonary Embolism TreatmentBleeding complications were considered major: (1) if the hemorrhage caused a significant clinical event, or (2) if accompanied by a hemoglobin decrease 2 g/dL or transfusion of 2 or more units of blood products. Retroperitoneal, intraocular, and intracranial hemorrhages were always considered major.
| Dosing Regimen All patients also received warfarin sodium (dose-adjusted according to PT to achieve an INR of 2.0 to 3.0) commencing within 72 hours of Enoxaparin Sodium Injection or standard heparin therapy and continuing for up to 90 days. |
|---|
| Indication | Enoxaparin Sodium Injection 1.5 mg/kg daily subcutaneously | Enoxaparin Sodium Injection 1 mg/kg q12h subcutaneously | Heparin aPTT Adjusted Intravenous Therapy |
|---|
| Treatment of DVT and PE | n = 298 5 (2%) | n = 559 9 (2%) | n = 554 9 (2%) |
Table 6 Major Bleeding Episodes in Unstable Angina and Non-Q-Wave Myocardial Infarction | Dosing Regimen |
|---|
| Indication | Enoxaparin Sodium Injection The rates represent major bleeding on study medication up to 12 hours after dose. 1 mg/kg q12h subcutaneously | Heparin* aPTT Adjusted Intravenous Therapy |
|---|
| Unstable Angina and Non-Q-Wave MI Aspirin therapy was administered concurrently (100 to 325 mg per day). Bleeding complications were considered major: (1) if the hemorrhage caused a significant clinical event, or (2) if accompanied by a hemoglobin decrease by 3 g/dL or transfusion of 2 or more units of blood products. Intraocular, retroperitoneal, and intracranial hemorrhages were always considered major. | n = 1578 17 (1%) | n = 1529 18 (1%) |
Table 7 Major Bleeding Episodes in Acute ST-Segment Elevation Myocardial Infarction | Dosing Regimen |
|---|
| Indication | Enoxaparin Sodium Injection The rates represent major bleeding (including ICH) up to 30 days Initial 30 mg intravenous bolus followed by 1 mg/kg q12h subcutaneously | Heparin* aPTT Adjusted Intravenous Therapy |
|---|
| Acute ST-Segment Elevation | n = 10176 | n = 10151 |
| Myocardial Infarction | n (%) | n (%) |
| -Major bleeding (including ICH) Bleedings were considered major if the hemorrhage caused a significant clinical event associated with hemoglobin decrease by ≥ 5 g/dL. ICH were always considered major. | 211 (2.1) | 138 (1.4) |
| -Intracranial hemorrhages (ICH) | 84 (0.8) | 66 (0.7) |
Elevations of Serum Aminotransferases
Asymptomatic increases in aspartate (AST [SGOT]) and alanine (ALT [SGPT]) aminotransferase levels greater than three times the upper limit of normal of the laboratory reference range have been reported in up to 6.1% and 5.9% of patients, respectively, during
treatment with Enoxaparin Sodium Injection.
Since aminotransferase determinations are important in the differential diagnosis of myocardial infarction, liver disease, and pulmonary emboli, elevations that might be caused by drugs like Enoxaparin Sodium Injection should be interpreted with caution.
Local Reactions
Local irritation, pain, hematoma, ecchymosis, and erythema may follow subcutaneous injection of Enoxaparin Sodium Injection.
Adverse Reactions in Patients Receiving Enoxaparin Sodium Injection for Prophylaxis or Treatment of DVT, PE
Other adverse reactions that were thought to be possibly or probably related to treatment with Enoxaparin Sodium Injection, heparin, or placebo in clinical trials with patients undergoing hip or knee replacement surgery, abdominal or colorectal surgery, or treatment for DVT and that occurred at a rate of at least 2% in the Enoxaparin Sodium Injection group, are provided below (see Tables 8 to 11).
Table 8 Adverse Reactions Occurring at 2% Incidence in Enoxaparin Sodium Injection-Treated Patients Undergoing Abdominal or Colorectal Surgery | Dosing Regimen |
|---|
| Enoxaparin Sodium Injection 40 mg daily subcutaneously n = 1228 % | Heparin 5000 U q8h subcutaneously n = 1234 % |
|---|
| Adverse Reaction | Severe | Total | Severe | Total |
|---|
| Hemorrhage | <1 | 7 | <1 | 6 |
| Anemia | <1 | 3 | <1 | 3 |
| Ecchymosis | 0 | 3 | 0 | 3 |
Table 9 Adverse Reactions Occurring at 2% Incidence in Enoxaparin Sodium Injection-Treated Patients Undergoing Hip or Knee Replacement Surgery | Dosing Regimen |
|---|
| Enoxaparin Sodium Injection 40 mg daily subcutaneously | Enoxaparin Sodium Injection 30 mg q12h subcutaneously | Heparin 15,000 U/24h subcutaneously | Placebo q12h subcutaneously |
|---|
| Peri-operative Period | Extended Prophylaxis Period | | | |
|---|
| n = 288 Data represent Enoxaparin Sodium Injection 40 mg subcutaneously once a day initiated up to 12 hours prior to surgery in 288 hip replacement surgery patients who received Enoxaparin Sodium Injection peri-operatively in an unblinded fashion in one clinical trial. % | n = 131 Data represent Enoxaparin Sodium Injection 40 mg subcutaneously once a day given in a blinded fashion as extended prophylaxis at the end of the peri-operative period in 131 of the original 288 hip replacement surgery patients for up to 21 days in one clinical trial. % | n = 1080 % | n = 766 % | n = 115 % |
|---|
| Adverse Reaction | Severe | Total | Severe | Total | Severe | Total | Severe | Total | Severe | Total |
|---|
| Fever | 0 | 8 | 0 | 0 | <1 | 5 | <1 | 4 | 0 | 3 |
| Hemorrhage | <1 | 13 | 0 | 5 | <1 | 4 | 1 | 4 | 0 | 3 |
| Nausea | | | | | <1 | 3 | <1 | 2 | 0 | 2 |
| Anemia | 0 | 16 | 0 | <2 | <1 | 2 | 2 | 5 | <1 | 7 |
| Edema | | | | | <1 | 2 | <1 | 2 | 0 | 2 |
| Peripheral edema | 0 | 6 | 0 | 0 | <1 | 3 | <1 | 4 | 0 | 3 |
Table 10 Adverse Reactions Occurring at ≥2% Incidence in Enoxaparin Sodium Injection-Treated Medical Patients with Severely Restricted Mobility During Acute Illness| Adverse Reaction | Dosing Regimen |
|---|
Enoxaparin Sodium Inj. 40 mg daily subcutaneously n = 360 % | Placebo daily subcutaneously n = 362 % |
|---|
| Dyspnea | 3.3 | 5.2 |
| Thrombocytopenia | 2.8 | 2.8 |
| Confusion | 2.2 | 1.1 |
| Diarrhea | 2.2 | 1.7 |
| Nausea | 2.5 | 1.7 |
Table 11 Adverse Reactions Occurring at ≥2% Incidence in Enoxaparin Sodium Injection-Treated Patients Undergoing Treatment of Deep Vein Thrombosis with or without Pulmonary Embolism| Adverse Event | Dosing Regimen |
|---|
Enoxaparin Sodium Injection 1.5 mg/kg daily subcutaneously n = 298 % | Enoxaparin Sodium Injection 1 mg/kg q12h subcutaneously n = 559 % | Heparin aPTT Adjusted Intravenous Therapy n = 544 % |
|---|
| Severe | Total | Severe | Total | Severe | Total |
|---|
| Injection Site Hemorrhage | 0 | 5 | 0 | 3 | <1 | <1 |
| Injection Site Pain | 0 | 2 | 0 | 2 | 0 | 0 |
| Hematuria | 0 | 2 | 0 | <1 | <1 | 2 |
Adverse Events in Enoxaparin Sodium Injection-Treated Patients with Unstable Angina or Non-Q-Wave Myocardial Infarction
Non-hemorrhagic clinical events reported to be related to Enoxaparin Sodium Injection therapy occurred at an incidence of ≤ 1%.
Non-major hemorrhagic events, primarily injection site ecchymosis and hematomas, were more frequently reported in patients treated with subcutaneous Enoxaparin Sodium Injection than in patients treated with intravenous heparin.
Serious adverse events with Enoxaparin Sodium Injection or heparin in a clinical trial in patients with unstable angina or non-Q-wave myocardial infarction that occurred at a rate of at least 0.5% in the Enoxaparin Sodium Injection group are provided below (see Table 12).
Table 12 Serious Adverse Events Occurring at ≥ 0.5% Incidence in Enoxaparin Sodium Injection-Treated Patients with Unstable Angina or Non-Q-Wave Myocardial Infarction| Adverse Event | Dosing Regimen |
|---|
Enoxaparin Sodium Injection 1 mg/kg q12h subcutaneously n = 1578 n (%) | Heparin aPTT Adjusted Intravenous Therapy n = 1529 n (%) |
|---|
| Atrial fibrillation | 11 (0.70) | 3 (0.20) |
| Heart failure | 15 (0.95) | 11 (0.72) |
| Lung edema | 11 (0.70) | 11 (0.72) |
| Pneumonia | 13 (0.82) | 9 (0.59) |
Adverse Reactions in Enoxaparin Sodium Injection-Treated Patients with Acute ST-Segment Elevation Myocardial Infarction
In a clinical trial in patients with acute ST-segment elevation myocardial infarction, thrombocytopenia occurred at a rate of 1.5%.
Risk Summary
Placental transfer of enoxaparin was observed in the animal studies. Human data from a retrospective cohort study, which included 693 live births, suggest that enoxaparin does not increase the risk of major developmental abnormalities (see Data). Based on animal data, Enoxaparin Sodium Injection is not predicted to increase the risk of major developmental abnormalities (see Data).
Adverse outcomes in pregnancy occur regardless of the health of the mother or the use of medications. The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown. In the U.S. general population, the estimated background
risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.
Clinical Considerations
Pregnancy alone confers an increased risk for thromboembolism that is even higher for women with thromboembolic disease and certain high risk pregnancy conditions. While not adequately studied, pregnant women with mechanical prosthetic heart valves may be at even higher risk for thrombosis [see Warnings and Precautions (5.7) and Use in Specific Populations (8.6)]. Pregnant women with thromboembolic disease, including those with mechanical prosthetic heart valves and those with inherited or acquired thrombophilias, have an increased risk of other maternal complications and fetal loss regardless of the type of anticoagulant used.
All patients receiving anticoagulants, including pregnant women, are at risk for bleeding. Pregnant women receiving Enoxaparin Sodium Injection should be carefully monitored for evidence of bleeding or excessive anticoagulation. Consideration for use of a shorter acting anticoagulant should be specifically addressed as delivery approaches [see Boxed Warning]. Hemorrhage can occur at any site and may lead to death of mother and/or fetus. Pregnant women should be apprised of the potential hazard to the fetus and the mother if Enoxaparin Sodium Injection is administered during pregnancy.
It is not known if monitoring of anti-Factor Xa activity and dose adjustment (by weight or anti-Factor Xa activity) of Enoxaparin Sodium Injection affect the safety and the efficacy of the drug during pregnancy.
Cases of “gasping syndrome” have occurred in premature infants when large amounts of benzyl alcohol have been administered (99-405 mg/kg/day). The multiple-dose vial of Enoxaparin Sodium Injection contains 15 mg benzyl alcohol per 1 mL as a preservative [see
Warnings and Precautions (5.8)].
Data
Human Data
There are no adequate and well-controlled studies in pregnant women. A retrospective study reviewed the records of 604 women who used Enoxaparin Sodium Injection during pregnancy. A total of 624 pregnancies resulted in 693 live births. There were 72 hemorrhagic
events (11 serious) in 63 women. There were 14 cases of neonatal hemorrhage. Major congenital anomalies in live births occurred at rates (2.5%) similar to background rates. There have been postmarketing reports of fetal death when pregnant women received Enoxaparin Sodium Injection. Causality for these cases has not been determined.
Insufficient data, the underlying disease, and the possibility of inadequate anticoagulation complicate the evaluation of these cases.
A clinical study using Enoxaparin Sodium Injection in pregnant women with mechanical prosthetic heart valves has been conducted [see Warnings and Precautions (5.7)].
Animal data
Teratology studies have been conducted in pregnant rats and rabbits at subcutaneous doses of enoxaparin up to 15 times the recommended human dose (by comparison with 2 mg/kg as the maximum recommended daily dose). There was no evidence of teratogenic effects or fetotoxicity due to enoxaparin. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.
Prevention of Deep Vein Thrombosis in Hip, Knee and Abdominal Surgery; Treatment of Deep Vein Thrombosis, Prevention of Ischemic Complications of Unstable Angina and Non-Q-Wave Myocardial Infarction
Over 2800 patients, 65 years and older, have received Enoxaparin Sodium Injection in clinical trials. The efficacy of Enoxaparin Sodium Injection in the geriatric (≥65 years) was similar to that seen in younger patients (<65 years). The incidence of bleeding complications was similar between geriatric and younger patients when 30 mg every 12 hours or 40 mg once a day doses of Enoxaparin Sodium Injection were employed. The incidence of bleeding complications was higher in geriatric patients as compared to younger patients when Enoxaparin Sodium Injection was administered at doses of 1.5 mg/kg once a day or 1 mg/kg every 12 hours. The risk of Enoxaparin Sodium Injection-associated bleeding increased with age. Serious adverse events increased with age for patients receiving Enoxaparin Sodium Injection. Other clinical experience (including postmarketing surveillance and literature reports) has not revealed additional differences in the safety of Enoxaparin Sodium Injection between geriatric and younger patients. Careful attention to dosing intervals and concomitant medications (especially antiplatelet medications) is advised. Enoxaparin Sodium Injection should be used with care in geriatric patients who may show delayed elimination of enoxaparin. Monitoring of geriatric patients with low body weight (<45 kg) and those predisposed to decreased renal function should be considered [see Warnings and Precautions (2.6) and Clinical Pharmacology (12.3)].
Treatment of Acute ST-Segment Elevation Myocardial Infarction
In the clinical study for treatment of acute ST-segment elevation myocardial infarction, there was no evidence of difference in efficacy between patients ≥75 years of age (n = 1241) and patients less than 75 years of age (n = 9015). Patients ≥75 years of age did not receive a 30 mg intravenous bolus prior to the normal dosage regimen and had their subcutaneous dose adjusted to 0.75 mg/kg every 12 hours [see Dosage and Administration (2.4)]. The incidence of bleeding complications was higher in patients ≥65 years of age as compared to younger patients (<65 years).
Enoxaparin Sodium Injection USP 100 mg/mL Concentration contains 10 mg enoxaparin sodium (approximate anti-Factor Xa activity of 1000 IU [with reference to the W.H.O. First International Low Molecular Weight Heparin Reference Standard]) per 0.1 mL Water for Injection.
Enoxaparin Sodium Injection USP 150 mg/mL Concentration contains 15 mg enoxaparin sodium (approximate anti-Factor Xa activity of 1500 IU [with reference to the W.H.O. First International Low Molecular Weight Heparin Reference Standard]) per 0.1 mL Water for Injection.
The Enoxaparin Sodium Injection USP prefilled syringes and graduated prefilled syringes are preservative-free and intended for use only as a single-dose injection. The multiple-dose vial contains 15 mg benzyl alcohol per 1 mL as a preservative [see Dosage and Administration (2) and How Supplied/Storage and Handling(16)].
Absorption
Pharmacokinetic trials were conducted using the 100 mg/mL formulation. Maximum anti-Factor Xa and anti-thrombin (anti-Factor IIa) activities occur 3 to 5 hours after subcutaneous injection of enoxaparin. Mean peak anti-Factor Xa activity was 0.16 IU/mL (1.58 mcg/mL) and 0.38 IU/mL (3.83 mcg/mL) after the 20 mg and the 40 mg clinically tested subcutaneous doses, respectively. Mean (n = 46) peak anti-Factor Xa activity was 1.1 IU/mL at steady state in patients with unstable angina receiving 1 mg/kg subcutaneously every 12 hours for 14 days. Mean absolute bioavailability of enoxaparin, after 1.5 mg/kg given subcutaneously, based on anti-Factor Xa activity is approximately 100% in healthy subjects.
A 30 mg intravenous bolus immediately followed by a 1 mg/kg subcutaneously every 12 hours provided initial peak anti-Factor Xa levels of 1.16 IU/mL (n=16) and average exposure corresponding to 84% of steady-state levels. Steady state is achieved on the second day of treatment.
Enoxaparin pharmacokinetics appear to be linear over the recommended dosage ranges [see Dosage and Administration (2)]. After repeated subcutaneous administration of 40 mg once daily and 1.5 mg/kg once-daily regimens in healthy volunteers, the steady state is reached on day 2 with an average exposure ratio about 15% higher than after a single dose. Steady-state enoxaparin activity levels are well predicted by single-dose pharmacokinetics. After repeated subcutaneous administration of the 1 mg/kg twice-daily regimen, the steady state is reached from day 4 with mean exposure about 65% higher than after a single dose and mean peak and trough levels of about 1.2 and 0.52 IU/mL, respectively. Based on enoxaparin sodium pharmacokinetics, this difference in steady state is expected and within the therapeutic range.
Although not studied clinically, the 150 mg/mL concentration of enoxaparin sodium is projected to result in anticoagulant activities similar to those of 100 mg/mL and 200 mg/mL concentrations at the same enoxaparin dose. When a daily 1.5 mg/kg subcutaneous injection of enoxaparin sodium was given to 25 healthy male and female subjects using a 100 mg/mL or a 200 mg/mL concentration the following pharmacokinetic profiles were obtained (see Table 13).
Table 13 Pharmacokinetic Parameters* After 5 Days of 1.5 mg/kg Subcutaneous Once Daily Doses of Enoxaparin Sodium Using 100 mg/mL or 200 mg/mL Concentrations | Concentration | Anti-Xa | Anti-IIa | Heptest | aPTT |
|---|
Amax (IU/mL or sec) | 100 mg/mL | 1.37 (±0.23) | 0.23 (±0.05) | 105 (±17) | 19 (±5) |
| 200 mg/mL | 1.45 (±0.22) | 0.26 (±0.05) | 111 (±17) | 22 (±7) |
| 90% CI | 102%-110% | | 102%-111% | |
| tmax Median (range) (h) | 100 mg/mL | 3 (2-6) | 4 (2-5) | 2.5 (2-4.5) | 3 (2-4.5) |
| 200 mg/mL | 3.5 (2-6) | 4.5 (2.5-6) | 3.3 (2-5) | 3 (2-5) |
AUC (ss) (hMeans ± SD at Day 5 and 90% Confidence Interval (CI) of the ratio IU/mL or h† sec) | 100 mg/mL | 14.26 (±2.93) | 1.54 (±0.61) | 1321 (±219) | |
| 200 mg/mL | 15.43 (±2.96) | 1.77 (±0.67) | 1401 (±227) | |
| 90% CI | 105%-112% | | 103%-109% | |
Distribution
The volume of distribution of anti-Factor Xa activity is about 4.3 L.
Elimination
Following intravenous dosing, the total body clearance of enoxaparin is 26 mL/min.After intravenous dosing of enoxaparin labeled with the gamma-emitter, 99mTc, 40% of radioactivity and 8 to 20% of anti-Factor Xa activity were recovered in urine in 24 hours. Elimination half-life based on anti-Factor Xa activity was 4.5 hours after a single subcutaneous dose to about 7 hours after repeated dosing. Significant anti-Factor Xa activity persists in plasma for about 12 hours following a 40 mg subcutaneous once a day dose.
Following subcutaneous dosing, the apparent clearance (CL/F) of enoxaparin is approximately 15 mL/min.
Metabolism
Enoxaparin sodium is primarily metabolized in the liver by desulfation and/or depolymerization to lower molecular weight species with much reduced biological potency. Renal clearance of active fragments represents about 10% of the administered dose and total renal excretion of active and non-active fragments 40% of the dose.
Special Populations
Gender
Apparent clearance and Amax derived from anti-Factor Xa values following single subcutaneous dosing (40 mg and 60 mg) were slightly higher in males than in females. The source of the gender difference in these parameters has not been conclusively identified; however, body weight may be a contributing factor.
Geriatric
Apparent clearance and Amax derived from anti-Factor Xa values following single and multiple subcutaneous dosing in geriatric subjects were close to those observed in young subjects. Following once a day subcutaneous dosing of 40 mg enoxaparin, the Day 10 mean area under anti-Factor Xa activity versus time curve (AUC) was approximately 15% greater than the mean Day 1 AUC value [see Dosage and Administration (2.4) and Use in Specific Populations (8.5)].
Renal impairment
A linear relationship between anti-Factor Xa plasma clearance and creatinine clearance at steady state has been observed, which indicates decreased clearance of enoxaparin sodium in patients with reduced renal function. Anti-Factor Xa exposure represented by AUC, at steady state, is marginally increased in patients with creatinine clearance 50 to 80 mL/min and patients with creatinine clearance 30 to <50 mL/min renal impairment after repeated subcutaneous 40 mg once-daily doses. In patients with severe renal impairment (creatinine clearance <30 mL/min), the AUC at steady state is significantly increased on average by 65% after repeated subcutaneous 40 mg once-daily doses [see Dosage and Administration (2.3) and Use in Specific Populations (8.7)].
Hemodialysis
In a single study, elimination rate appeared similar but AUC was two-fold higher than control population, after a single 0.25 or 0.5 mg/kg intravenous dose.
Hepatic Impairment
Studies with Enoxaparin Sodium Injection in patients with hepatic impairment have not been conducted and the impact of hepatic impairment on the exposure to enoxaparin is unknown.
Weight
After repeated subcutaneous 1.5 mg/kg once daily dosing, mean AUC of anti-Factor Xa activity is marginally higher at steady state in obese healthy volunteers (BMI 30-48 kg/m2) compared to non-obese control subjects, while Amax is not increased.
When non-weight adjusted dosing was administered, it was found after a single-subcutaneous 40 mg dose, that anti-Factor Xa exposure is 52% higher in low-weight women (<45 kg) and 27% higher in low-weight men (< 57 kg) when compared to normal weight control subjects [see Use in Specific Populations (8.8)].
Pharmacokinetic interaction
No pharmacokinetic interaction was observed between Enoxaparin Sodium Injection and thrombolytics when administered concomitantly.
Amphastar Pharmaceuticals, Inc.
Rancho Cucamonga, CA 91730 U.S.A.
Rev. 12/18
6956016AK