ARIXTRA

ARIXTRA (fondaparinux sodium injection, USP) is a sterile solution containing fondaparinux sodium. It is a synthetic and specific inhibitor of activated Factor X (Xa). Fondaparinux sodium is methyl O -2-deoxy-6- O -sulfo-2-(sulfoamino)-α-D-glucopyranosyl-(1→4)- O -β-D-glucopyra-nuronosyl-(1→4)- O -2-deoxy-3,6-di- O -sulfo-2-(sulfoamino)-α-D-glucopyranosyl-(1→4)- O -2- O -sulfo-α-L-idopyranuronosyl-(1→4)-2-deoxy-6- O -sulfo-2-(sulfoamino)-α-D-glucopyranoside, decasodium salt. The molecular formula of fondaparinux sodium is C 31 H 43 N 3 Na 10 O 49 S 8 and its molecular weight is 1728. The structural formula is provided below: ARIXTRA is supplied as a sterile, preservative-free injectable solution for subcutaneous use. Each single-dose, prefilled syringe of ARIXTRA, affixed with an automatic needle protection system, contains 2.5 mg of fondaparinux sodium in 0.5 mL, 5 mg of fondaparinux sodium in 0.4 mL, 7.5 mg of fondaparinux sodium in 0.6 mL, or 10 mg of fondaparinux sodium in 0.8 mL of an isotonic solution of sodium chloride and water for injection. May also contain sodium hydroxide and/or hydrochloric acid as pH adjusters. The final drug product is a clear and colorless to slightly yellow liquid with a pH between 5 and 8. fondaparinux sodium structural formula

ARIXTRA is a Factor Xa inhibitor (anticoagulant) indicated for: • Prophylaxis of deep vein thrombosis (DVT) in adult patients undergoing hip fracture surgery (including extended prophylaxis), hip replacement surgery, knee replacement surgery, or abdominal surgery. ( 1.1 ) • Treatment of DVT or acute pulmonary embolism (PE) in adult patients when administered in conjunction with warfarin sodium. ( 1.2 , 1.3 ) • Treatment of venous thromboembolism (VTE) in pediatric patients aged 1 year or older weighing at least 10 kg. ( 1.4 ) 1.1 Prophylaxis of Deep Vein Thrombosis in Adult Patients ARIXTRA ® is indicated for the prophylaxis of deep vein thrombosis (DVT) in adults, which may lead to pulmonary embolism (PE): • in patients undergoing hip fracture surgery, including extended prophylaxis; • in patients undergoing hip replacement surgery; • in patients undergoing knee replacement surgery; • in patients undergoing abdominal surgery who are at risk for thromboembolic complications. 1.2 Treatment of Acute Deep Vein Thrombosis in Adult Patients ARIXTRA is indicated for the treatment of acute deep vein thrombosis in adults when administered in conjunction with warfarin sodium. 1.3 Treatment of Acute Pulmonary Embolism in Adult Patients ARIXTRA is indicated for the treatment of acute pulmonary embolism in adults when administered in conjunction with warfarin sodium when initial therapy is administered in the hospital. 1.4 Treatment of Venous Thromboembolism in Pediatric Patients ARIXTRA is indicated for the treatment of venous thromboembolism (VTE) in pediatric patients aged 1 year or older weighing at least 10 kg.

• For subcutaneous use, do not mix with other injections or infusions. ( 2.1 ) • Prophylaxis of deep vein thrombosis in adults: ARIXTRA 2.5 mg subcutaneously once daily after hemostasis has been established. The initial dose should be given no earlier than 6 hours to 8 hours after surgery and continued for 5 days to 9 days. For patients undergoing hip fracture surgery, extended prophylaxis up to 24 additional days is recommended. ( 2.2 , 2.3 ) • Treatment of deep vein thrombosis and pulmonary embolism in adults: ARIXTRA 5 mg (body weight less than 50 kg), 7.5 mg (50 kg to 100 kg), or 10 mg (greater than 100 kg) subcutaneously once daily. Treatment should continue for at least 5 days until INR 2 to 3 is achieved with warfarin sodium. ( 2.4 ) • Treatment of venous thromboembolism in pediatric patients weighing at least 10 kg: ARIXTRA 0.1 mg/kg subcutaneously once daily. ( 2.5 ) 2.1 Important Dosing Information Do not mix other medications or solutions with ARIXTRA. Administer ARIXTRA only subcutaneously. Discard unused portion. Monitor routine complete blood counts (including platelet count), serum creatinine level, and stool occult blood periodically [see Warnings and Precautions (5.6) ] . 2.2 Deep Vein Thrombosis Prophylaxis Following Hip Fracture, Hip Replacement, and Knee Replacement Surgery in Adults In adult patients undergoing hip fracture, hip replacement, or knee replacement surgery, the recommended dose of ARIXTRA is 2.5 mg administered by subcutaneous injection once daily after hemostasis has been established. Administer the initial dose no earlier than 6 hours to 8 hours after surgery. Administration of ARIXTRA earlier than 6 hours after surgery increases the risk of major bleeding. The usual duration of therapy is 5 days to 9 days; up to 11 days of therapy was administered in clinical trials. In patients undergoing hip fracture surgery, an extended prophylaxis course of up to 24 additional days is recommended. In patients undergoing hip fracture surgery, a total of 32 days (peri-operative and extended prophylaxis) was administered in clinical trials [see Warnings and Precautions (5.6) , Adverse Reactions (6) , and Clinical Studies (14) ] . 2.3 Deep Vein Thrombosis Prophylaxis Following Abdominal Surgery in Adults In adult patients undergoing abdominal surgery, the recommended dose of ARIXTRA is 2.5 mg administered by subcutaneous injection once daily after hemostasis has been established. Administer the initial dose no earlier than 6 hours to 8 hours after surgery. Administration of ARIXTRA earlier than 6 hours after surgery increases the risk of major bleeding. The usual duration of administration is 5 days to 9 days, and up to 10 days of ARIXTRA was administered in clinical trials. 2.4 Deep Vein Thrombosis and Pulmonary Embolism Treatment in Adults In adult patients with acute symptomatic DVT and in patients with acute symptomatic PE, the recommended dose of ARIXTRA is 5 mg (body weight less than 50 kg), 7.5 mg (body weight 50 kg to 100 kg), or 10 mg (body weight greater than 100 kg) by subcutaneous injection once daily (ARIXTRA treatment regimen). Initiate concomitant treatment with warfarin sodium as soon as possible, usually within 72 hours. Continue treatment with ARIXTRA for at least 5 days and until a therapeutic oral anticoagulant effect is established (INR 2 to 3). The usual duration of administration of ARIXTRA is 5 days to 9 days; up to 26 days of ARIXTRA injection was administered in clinical trials [see Warnings and Precautions (5.6) , Adverse Reactions (6) , and Clinical Studies (14) ] . 2.5 Venous Thromboembolism Treatment in Pediatric Patients Aged 1 Year or Older Weighing at Least 10 kg For patients weighing 10 kg to 20 kg, the recommended initial dose is 0.1 mg/kg subcutaneously once daily. There is no available prefilled syringe for patients in this weight range, and a patient specific dose should be prepared ( see section 2.8 Instructions for Preparation of Individual Pediatric Doses in Pharmacies ). The dose should be exact and rounded to the nearest 0.1 mg ( see Table 1 ). Table 1. Recommended Initial Dose of ARIXTRA for Treatment of VTE in Pediatric Patients Weighing 10 kg to 20 kg Body Weight (kg) Initial Dose 10 kg to 20 kg Dosing should be exact and rounded to the nearest 0.1 mg For patients weighing over 20 kg, the recommended initial dose is 0.1 mg/kg subcutaneously once daily with doses rounded to the nearest prefilled syringe according to Table 2 . There is no available information for dosing pediatric patients who weigh less than 10 kg. Table 2. Recommended Prefilled Syringe Selection for Initial Dose of ARIXTRA for Treatment of VTE in Pediatric Patients Weighing More Than 20 kg Body Weight (kg) Prefilled Syringe Selection Greater than 20 kg to 40 kg Whenever possible, patients weighing more than 20 kg should receive a full prefilled syringe for dosing. If therapeutic levels are not achievable using the prefilled syringe available strengths and dose adjustments are needed, a patient specific dose may be prepared ( see section 2.8 Instructions for Preparation of Individual Pediatric Doses in Pharmacies ). 2.5 mg/0.5 mL Greater than 40 kg to 60 kg 5 mg/0.4 mL Greater than 60 kg 7.5 mg/0.6 mL Monitor fondaparinux levels 2 hours to 4 hours after the second or third dose and then weekly for a month followed by every 1 month to 3 months for the duration of treatment using a fondaparinux-based anti-Xa assay with a therapeutic goal range of 0.5 mg/L to 1 mg/L. Dosing adjustments may be necessary to achieve peak blood concentration within the therapeutic target of 0.5 mg/L to 1 mg/L ( see Table 3 ). Do not exceed the maximum dose of 7.5 mg/day. Table 3. Recommended Dose Adjustments Fondaparinux-Based Anti-Xa Level (mg/L) Dose Adjustment Less than 0.3 mg/L Increase dose by 0.03 mg/kg Adjust the dose to the nearest 0.1 mg. 0.3 mg/L to 0.49 mg/L Increase dose by 0.01 mg/kg 0.5 mg/L to 1 mg/L No change 1.01 mg/L to 1.2 mg/L Decrease dose by 0.01 mg/kg Greater than 1.2 mg/L Decrease dose by 0.03 mg/kg There is no adequate data to support the use of ARIXTRA in pediatric patients below 1 year of age. 2.6 Hepatic Impairment No dose adjustment is recommended in patients with mild to moderate hepatic impairment, based upon single-dose pharmacokinetic data. Pharmacokinetic data are not available for patients with severe hepatic impairment. Patients with hepatic impairment may be particularly vulnerable to bleeding during ARIXTRA therapy. Observe these patients closely for signs and symptoms of bleeding [see Clinical Pharmacology (12.4) ] . 2.7 Instructions for Use for Prefilled Syringe ARIXTRA Injection is provided in a single-dose, prefilled syringe affixed with an automatic needle protection system. ARIXTRA is administered by subcutaneous injection. It must not be administered by intramuscular injection. ARIXTRA is intended for use under a physician’s guidance. Patients may self-inject only if their physician determines that it is appropriate, and the patients are trained in subcutaneous injection techniques. Prior to administration, visually inspect ARIXTRA to ensure the solution is clear and free of particulate matter. To avoid the loss of drug when using the prefilled syringe, do not expel the air bubble from the syringe before the injection. Administration should be made in the fatty tissue, alternating injection sites (e.g., between the left and right anterolateral or the left and right posterolateral abdominal wall). To administer ARIXTRA: 1. Wipe the surface of the injection site with an alcohol swab. 2. Hold the syringe with either hand and use your other hand to twist the rigid needle guard (covers the needle) counter-clockwise. Pull the rigid needle guard straight off the needle (Figure A). Discard the needle guard. 3. Do not try to remove the air bubbles from the syringe before giving the injection. 4. Pinch a fold of skin at the injection site between your thumb and forefinger and hold it throughout the injection. 5. Hold the syringe with your thumb on the top pad of the plunger rod and your next 2 fingers on the finger grips on the syringe barrel. Pay attention to avoid sticking yourself with the exposed needle. 6. Insert the full length of the syringe needle perpendicularly into the skin fold held between the thumb and forefinger (Figure B). 7. Push the plunger rod firmly with your thumb as far as it will go. This will ensure you have injected all the contents of the syringe (Figure C). 8. When you have injected all the contents of the syringe, the plunger should be released. The plunger will then rise automatically while the needle withdraws from the skin and retracts into the security sleeve. Discard the syringe into the sharps container. 9. You will know that the syringe has worked when: • The needle is pulled back into the security sleeve and the white safety indicator appears above the upper body. • You may also hear or feel a soft click when the plunger rod is released fully. 2.7 Figure A 2.7 Figure B 2.7 Figure C 2.8 Instructions for Preparation of Individual Pediatric Doses in Pharmacies For pediatric patients weighing 10 kg to 20 kg, a patient-specific dose may be prepared by a pharmacist under aseptic conditions per the instructions below. These instructions may also be used to prepare pediatric patient-specific doses for patients weighing over 20 kg when dose adjustments are needed and therapeutic levels are not achievable using the prefilled syringe available strengths. Prior to preparing ARIXTRA, visually inspect ARIXTRA prefilled syringe to ensure the solution is clear and free of particulate matter. General Aseptic Preparation Practices Strictly observe aseptic technique when preparing patient specific pediatric doses of ARIXTRA. To prevent accidental contamination, prepare ARIXTRA according to aseptic standards, including but not limited to: • Prepare ARIXTRA in an ISO Class 5 laminar airflow (LAF) hood • Ensure that the dose preparation area, including the LAF hood, has appropriate environmental specifications, confirmed by periodic monitoring. • Ensure that personnel are appropriately trained in aseptic manipulations of sterile products. • Ensure that personnel wear appropriate clothing and gloves. • Ensure that gloves and surfaces are disinfected. All steps should be completed in accordance with aseptic techniques: 1. Determine the total dose and volume per the duration, and the appropriate number of ARIXTRA prefilled syringes. One ARIXTRA prefilled syringe is used in cases where the total required dose is less than 0.5 mL. Where the total dose required is greater than or equal to 0.5 mL, only two ARIXTRA prefilled syringes may be pooled together. The maximum number of ARIXTRA prefilled syringes that may be pooled together is two. Do not combine ARIXTRA prefilled syringes of different concentrations in one injection to give the prescribed dose. 2. Gather the required supplies including the appropriate ARIXTRA prefilled syringe(s), a sterile, closed/sealed, empty glass vial (recommended 5 mL), and required number of suitable sized graduated tuberculin sterile syringes with 27 gauge x ½” staked needles or sterile needles (if not pre-attached to syringe). 3. Verify the required supplies are correct and within expiry date. Ensure only the materials required for the preparation are present in the work area. 4. While wearing sterile gloves, clean the LAF hood and wipe it down with sterile 70% alcohol. Ensure the LAF hood is within specification and continually monitored. 5. Ensure equipment and consumables are cleaned with isopropyl alcohol (IPA). 6. Before transferring into the LAF hood, clean all supplies including ancillary items (such as vial holder jigs, syringe cap holder jigs, sharps containers) with IPA. 7. Perform all the dose preparation steps within the LAF hood. 8. Pre-sterilize gloves with IPA. While wearing sterile gloves, hold the ARIXTRA prefilled syringe with either gloved hand and use your other gloved hand to twist the rigid needle guard (covers the needle) counter-clockwise. Pull the rigid needle guard straight off the needle. Discard the needle guard. 9. Dispense the full contents of the ARIXTRA prefilled syringe into the vial by fully depressing the plunger. 10. When you have injected all the contents of the ARIXTRA prefilled syringe, the plunger should be released. The plunger will then rise automatically while the needle retracts into the security sleeve. Discard the ARIXTRA prefilled syringe into a sharps container. 11. Take an empty graduated tuberculin sterile syringe and attach a suitable sterile needle if not already supplied pre-attached. 12. Remove needle cap. 13. Withdraw required dose from vial into the tuberculin syringe. 14. Replace needle cap over the needle. Clean the external surfaces of the filled tuberculin syringe with IPA. 15. Repeat steps 11 to 14 as required for the appropriate number of tuberculin syringes necessary for the patient. 16. Label each ARIXTRA tuberculin syringe with patient specific information (e.g., dosing instructions, patient information), storage information (e.g., store refrigerated between 36°F to 46°F (2°C to 8°C), do not freeze, and the beyond use date). The beyond use date should be the earlier of the product expiration date of the ARIXTRA prefilled syringe or 30 days after preparation of the tuberculin syringe. 17. Prepared tuberculin syringes may be dispensed in an empty plastic bag. Include Patient Information and Instructions for Use for the tuberculin syringe within the plastic bag to be dispensed to patients. They may be stored at refrigerated temperatures between 36°F to 46°F (2°C to 8°C) for up to the beyond use date. Do not freeze. Do not store the pediatric preparations at room temperature as they are growth promoting at room temperature. Discard unused portion.

ARIXTRA is contraindicated in the following conditions: • Severe renal impairment (creatinine clearance [CrCl] less than 30 mL/min) [see Warnings and Precautions (5.3) and Use in Specific Populations (8.6) ] . • Active major bleeding. • Bacterial endocarditis. • Thrombocytopenia associated with a positive in vitro test for anti-platelet antibody in the presence of fondaparinux sodium. • Body weight less than 50 kg (venous thromboembolism [VTE] prophylaxis in adults only) [see Warnings and Precautions (5.4) ] . • History of serious hypersensitivity reaction (e.g., angioedema, anaphylactoid/anaphylactic reactions) to ARIXTRA. ARIXTRA is contraindicated in the following conditions: ( 4 ) • Severe renal impairment (creatinine clearance less than 30 mL/min) in prophylaxis or treatment of venous thromboembolism. • Active major bleeding. • Bacterial endocarditis. • Thrombocytopenia associated with a positive in vitro test for anti-platelet antibody in the presence of fondaparinux sodium. • Body weight less than 50 kg (venous thromboembolism prophylaxis in adults only). • History of serious hypersensitivity reaction (e.g., angioedema, anaphylactoid/anaphylactic reactions) to ARIXTRA.

The following clinically significant adverse reactions are described elsewhere in the labeling: • Spinal or epidural hematomas [see Warnings and Precautions (5.1) ] • Hemorrhage [see Warnings and Precautions (5.2) ] • Renal impairment and bleeding risk [see Warnings and Precautions (5.3) ] • Body weight less than 50 kg and bleeding risk [see Warnings and Precautions (5.4) ] • Thrombocytopenia [see Warnings and Precautions (5.5) ] The most serious adverse reactions associated with the use of ARIXTRA are bleeding complications. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Mylan at 1-877-446-3679 (1-877-4-INFO-RX) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Clinical Trials Experience in Adults The adverse reaction information below is based on data from 8,877 patients exposed to ARIXTRA in controlled trials of hip fracture, hip replacement, major knee, or abdominal surgeries, and DVT and PE treatment. Hemorrhage During administration of ARIXTRA, the most common adverse reactions were bleeding complications [see Warnings and Precautions (5.2) ] . Hip Fracture, Hip Replacement, and Knee Replacement Surgery The rates of major bleeding events reported during 3 active-controlled peri-operative VTE prophylaxis trials with enoxaparin sodium in hip fracture, hip replacement, or knee replacement surgery (N = 3,616) and in an extended VTE prophylaxis trial (n = 327) with ARIXTRA 2.5 mg are provided in Table 5. Table 5. Bleeding Across Randomized, Controlled Hip Fracture, Hip Replacement, and Knee Replacement Surgery Studies Peri-Operative Prophylaxis (Day 1 to Day 7 ± 1 post-surgery) Extended Prophylaxis (Day 8 to Day 28 ± 2 post-surgery) ARIXTRA 2.5 mg subcutaneously once daily N = 3,616 Enoxaparin Sodium Enoxaparin sodium dosing regimen: 30 mg every 12 hours or 40 mg once daily. , Not approved for use in patients undergoing hip fracture surgery. N = 3,956 ARIXTRA 2.5 mg subcutaneously once daily N = 327 Placebo subcutaneously once daily N = 329 Major bleeding Major bleeding was defined as clinically overt bleeding that was (1) fatal, (2) bleeding at critical site (e.g., intracranial, retroperitoneal, intraocular, pericardial, spinal, or into adrenal gland), (3) associated with re-operation at operative site, or (4) with a bleeding index (BI) greater than or equal to 2. 96 (2.7%) 75 (1.9%) 8 (2.4%) 2 (0.6%) Hip fracture 18/831 (2.2%) 19/842 (2.3%) 8/327 (2.4%) 2/329 (0.6%) Hip replacement 67/2,268 (3.0%) 55/2,597 (2.1%) — — Knee replacement 11/517 (2.1%) 1/517 (0.2%) — — Fatal bleeding 0 (0%) 1 (less than 0.1%) 0 (0%) 0 (0%) Non-fatal bleeding at critical site 0 (0%) 1 (less than 0.1%) 0 (0%) 0 (0%) Re-operation due to bleeding 12 (0.3%) 10 (0.3%) 2 (0.6%) 2 (0.6%) BI greater than or equal to 2 BI greater than or equal to 2: Overt bleeding associated only with a bleeding index (BI) greater than or equal to 2 calculated as [number of whole blood or packed red blood cell units transfused + [(pre-bleeding) – (post-bleeding)] hemoglobin (g/dL) values]. 84 (2.3%) 63 (1.6%) 6 (1.8%) 0 (0%) Minor bleeding Minor bleeding was defined as clinically overt bleeding that was not major. 109 (3%) 116 (2.9%) 5 (1.5%) 2 (0.6%) A separate analysis of major bleeding across all randomized, controlled, peri-operative, prophylaxis clinical studies of hip fracture, hip replacement, or knee replacement surgery according to the time of the first injection of ARIXTRA after surgical closure was performed in patients who received ARIXTRA only post-operatively. In this analysis, the incidences of major bleeding were as follows: less than 4 hours was 4.8% (5/104), 4 to 6 hours was 2.3% (28/1,196), 6 to 8 hours was 1.9% (38/1,965). In all studies, the majority (greater than or equal to 75%) of the major bleeding events occurred during the first 4 days after surgery. Abdominal Surgery In a randomized study of patients undergoing abdominal surgery, ARIXTRA 2.5 mg once daily (n = 1,433) was compared with dalteparin 5,000 IU once daily (n = 1,425). Bleeding rates are shown in Table 6. Table 6. Bleeding in the Abdominal Surgery Study ARIXTRA 2.5 mg subcutaneously once daily Dalteparin Sodium 5,000 IU subcutaneously once daily N = 1,433 N = 1,425 Major bleeding Major bleeding was defined as bleeding that was (1) fatal, (2) bleeding at the surgical site leading to intervention, (3) non-surgical bleeding at a critical site (e.g. intracranial, retroperitoneal, intraocular, pericardial, spinal, or into adrenal gland), or leading to an intervention, and/or with a bleeding index (BI) greater than or equal to 2. 49 (3.4%) 34 (2.4%) Fatal bleeding 2 (0.1%) 2 (0.1%) Non-fatal bleeding at critical site 0 (0%) 0 (0%) Other non-fatal major bleeding Surgical site 38 (2.7%) 26 (1.8%) Non-surgical site 9 (0.6%) 6 (0.4%) Minor bleeding Minor bleeding was defined as clinically overt bleeding that was not major. 31 (2.2%) 23 (1.6%) The rates of major bleeding according to the time interval following the first ARIXTRA injection were as follows: less than 6 hours was 3.4% (9/263) and 6 hours to 8 hours was 2.9% (32/1,112). Treatment of Deep Vein Thrombosis and Pulmonary Embolism The rates of bleeding events reported during a dose-response trial (n = 111) and an active-controlled trial with enoxaparin sodium in DVT treatment (n = 1,091) and an active-controlled trial with heparin in PE treatment (n = 1,092) with ARIXTRA are provided in Table 7. Table 7. Bleeding Bleeding rates are during the study drug treatment period (approximately 7 days). Patients were also treated with vitamin K antagonists initiated within 72 hours after the first study drug administration. in Deep Vein Thrombosis and Pulmonary Embolism Treatment Studies ARIXTRA N = 2,294 Enoxaparin Sodium N = 1,101 Heparin aPTT adjusted IV N = 1,092 Major bleeding Major bleeding was defined as clinically overt: – and/or contributing to death – and/or in a critical organ including intracranial, retroperitoneal, intraocular, spinal, pericardial, or adrenal gland – and/or associated with a fall in hemoglobin level greater than or equal to 2 g/dL – and/or leading to a transfusion greater than or equal to 2 units of packed red blood cells or whole blood. 28 (1.2%) 13 (1.2%) 12 (1.1%) Fatal bleeding 3 (0.1%) 0 (0%) 1 (0.1%) Non-fatal bleeding at a critical site 3 (0.1%) 0 (0%) 2 (0.2%) Intracranial bleeding 3 (0.1%) 0 (0%) 1 (0.1%) Retro-peritoneal bleeding 0 (0%) 0 (0%) 1 (0.1%) Other clinically overt bleeding Clinically overt bleeding with a 2 g/dL fall in hemoglobin and/or leading to transfusion of PRBC or whole blood greater than or equal to 2 units. 22 (1%) 13 (1.2%) 10 (0.9%) Minor bleeding Minor bleeding was defined as clinically overt bleeding that was not major. 70 (3.1%) 33 (3%) 57 (5.2%) Local Reactions Local irritation (injection site bleeding, rash, and pruritus) has occurred following subcutaneous injection of ARIXTRA. Elevations of Serum Aminotransferases In the peri-operative prophylaxis randomized clinical trials of 7 ± 2 days, asymptomatic increases in aspartate (AST) and alanine (ALT) aminotransferase levels greater than 3 times the upper limit of normal were reported in 1.7% and 2.6% of patients, respectively, during treatment with ARIXTRA 2.5 mg once daily versus 3.2% and 3.9% of patients, respectively, during treatment with enoxaparin sodium 30 mg every 12 hours or 40 mg once daily enoxaparin sodium. These elevations are reversible and may be associated with increases in bilirubin. In the extended prophylaxis clinical trial, no significant differences in AST and ALT levels between ARIXTRA 2.5 mg and placebo-treated patients were observed. In the DVT and PE treatment clinical trials, asymptomatic increases in AST and ALT levels greater than 3 times the upper limit of normal of the laboratory reference range were reported in 0.7% and 1.3% of patients, respectively, during treatment with ARIXTRA. In comparison, these increases were reported in 4.8% and 12.3% of patients, respectively, in the DVT treatment trial during treatment with enoxaparin sodium 1 mg/kg every 12 hours and in 2.9% and 8.7% of patients, respectively, in the PE treatment trial during treatment with aPTT adjusted heparin. 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 ARIXTRA should be interpreted with caution. Other Adverse Reactions Other adverse reactions that occurred during treatment with ARIXTRA in clinical trials with patients undergoing hip fracture, hip replacement, or knee replacement surgery are provided in Table 8. Table 8. Adverse Reactions Across Randomized, Controlled, Hip Fracture Surgery, Hip Replacement Surgery, and Knee Replacement Surgery Studies Adverse Reactions Peri-Operative Prophylaxis (Day 1 to Day 7 ± 1 post-surgery) Extended Prophylaxis (Day 8 to Day 28 ± 2 post-surgery) ARIXTRA 2.5 mg subcutaneously once daily Enoxaparin Sodium Enoxaparin sodium dosing regimen: 30 mg every 12 hours or 40 mg once daily. , Not approved for use in patients undergoing hip fracture surgery. ARIXTRA 2.5 mg subcutaneously once daily Placebo subcutaneously once daily N = 3,616 N = 3,956 N = 327 N = 329 Anemia 707 (19.6%) 670 (16.9%) 5 (1.5%) 4 (1.2%) Insomnia 179 (5%) 214 (5.4%) 3 (0.9%) 1 (0.3%) Wound drainage increased 161 (4.5%) 184 (4.7%) 2 (0.6%) 0 (0%) Hypokalemia 152 (4.2%) 164 (4.1%) 0 (0%) 0 (0%) Dizziness 131 (3.6%) 165 (4.2%) 2 (0.6%) 0 (0%) Purpura 128 (3.5%) 137 (3.5%) 0 (0%) 0 (0%) Hypotension 126 (3.5%) 125 (3.2%) 1 (0.3%) 0 (0%) Confusion 113 (3.1%) 132 (3.3%) 4 (1.2%) 1 (0.3%) Bullous eruption Localized blister coded as bullous eruption. 112 (3.1%) 102 (2.6%) 0 (0%) 1 (0.3%) Hematoma 103 (2.8%) 109 (2.8%) 7 (2.1%) 1 (0.3%) Post-operative hemorrhage 85 (2.4%) 69 (1.7%) 2 (0.6%) 2 (0.6%) The most common adverse reaction in the abdominal surgery trial was post-operative wound infection (4.9%), and the most common adverse reaction in the VTE treatment trials was epistaxis (1.3%). Clinical Trials Experience in Pediatric Patients Safety data for use of ARIXTRA in the treatment of VTE in pediatric patients aged 1 year or older is available from Study FDPX-IJS-7001. In Study FDPX-IJS-7001 (n = 366), the median duration of treatment with fondaparinux sodium injection, including ARIXTRA, was 85 days (range 1 day to 3,768 days). The incidence of major bleeding events, defined as per the ISTH criteria, was the primary safety outcome of interest in Study FDPX-IJS-7001. Seven patients (1.9%) had composite major bleeding events: 1 patient (0.3%) had clinically overt bleeding (associated with a decrease in hemoglobin of at least 20 g/L (2 g/dL) in a 24-hour period), 3 patients (0.8%) had bleeding that was retroperitoneal, pulmonary, intracranial, or otherwise involved the central nervous system, and 3 patients (0.8%) had major bleeding that required surgical intervention in an operating suite. Major bleeding events resulted in the interruption of fondaparinux sodium injection treatment for 4 patients and the discontinuation of fondaparinux sodium injection for 3 patients. All major bleeding events were reported in patients between the ages of greater than or equal to 2 years to less than 18 years. Eleven patients (3%) had non-major bleeding events: 8 patients (2.2%) had overt bleeding for which a blood product was administered, and which was not directly attributable to the patient’s underlying medical condition and 4 patients (1.1%) had bleeding that required medical or surgical intervention to restore hemostasis other than in an operating room. All non-major bleeding events warranted either interruption or withdrawal of fondaparinux sodium injection treatment except for 1 patient for whom the action taken with fondaparinux was not reported. All non-major bleeding events were reported in patients between the ages of greater than or equal to 2 years to less than 18 years. Overall, 65 patients (18%) had composite minor bleeding events: 64 patients (18%) had overt or macroscopic evidence of bleeding that did not fulfill the criteria for either major bleeding or clinically relevant, non-major bleeding and two patients (0.5%) had non-major menstrual bleeding which resulted in a medical consultation and/or intervention. Other Adverse Reactions Other adverse reactions that occurred during treatment with fondaparinux sodium injection in pediatric studies included: anemia, thrombocytopenia, allergic reactions, generalized skin associated events, abnormal liver function, hypokalemia, and hypotension. 6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of ARIXTRA. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. In the postmarketing experience, epidural or spinal hematoma has been reported in association with the use of ARIXTRA by subcutaneous (SC) injection [see Warnings and Precautions (5.1) ] . Occurrences of thrombocytopenia with thrombosis that manifested similar to heparin-induced thrombocytopenia have been reported in the postmarketing experience and cases of elevated aPTT temporally associated with bleeding events have been reported following administration of ARIXTRA (with or without concomitant administration of other anticoagulants) [see Warnings and Precautions (5.5) ] . Serious allergic reactions, including angioedema, anaphylactoid/anaphylactic reactions have been reported with the use of ARIXTRA [see Contraindications (4) ] . Elevations of hepatic transaminases have been reported in pediatric patients with elevations greater than 10x ULN.

In clinical studies performed with ARIXTRA, the concomitant use of oral anticoagulants (warfarin sodium), platelet inhibitors (acetylsalicylic acid), NSAIDs (piroxicam), and digoxin did not significantly affect the pharmacokinetics/pharmacodynamics of fondaparinux sodium. In addition, ARIXTRA neither influenced the pharmacodynamics of warfarin sodium, acetylsalicylic acid, piroxicam, and digoxin, nor the pharmacokinetics of digoxin at steady state. Agents that may enhance the risk of hemorrhage should be discontinued prior to initiation of therapy with ARIXTRA unless these agents are essential. If co-administration is necessary, monitor patients closely for hemorrhage [see Warnings and Precautions (5.2) ] . In an in vitro study in human liver microsomes, inhibition of CYP2A6 hydroxylation of coumarin by fondaparinux (200 micromolar i.e., 350 mg/L) was 17% to 28%. Inhibition of the other isozymes evaluated (CYPs 1A2, 2C9, 2C19, 2D6, 3A4, and 3E1) was 0% to 16%. Since fondaparinux does not markedly inhibit CYP450s (CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, or CYP3A4) in vitro , fondaparinux sodium is not expected to significantly interact with other drugs in vivo by inhibition of metabolism mediated by these isozymes. Since fondaparinux sodium does not bind significantly to plasma proteins other than ATIII, no drug interactions by protein-binding displacement are expected. Discontinue agents that may enhance the risk of hemorrhage prior to initiation of therapy with ARIXTRA unless essential. If co-administration is necessary, monitor patients closely for hemorrhage. ( 7 )