Argatroban

12.1 Mechanism of Action Argatroban is a direct thrombin inhibitor that reversibly binds to the thrombin active site. Argatroban does not require the co-factor antithrombin III for antithrombotic activity. Argatroban exerts its anticoagulant effects by inhibiting thrombin-catalyzed or -induced reactions, including fibrin formation; activation of coagulation factors V, VIII, and XIII; activation of protein C; and platelet aggregation. Argatroban inhibits thrombin with an inhibition constant (Ki) of 0.04 μM. At therapeutic concentrations, argatroban has little or no effect on related serine proteases (trypsin, factor Xa, plasmin, and kallikrein). Argatroban is capable of inhibiting the action of both free and clot-associated thrombin.

1 INDICATIONS AND USAGE Argatroban is a direct thrombin inhibitor indicated: For prophylaxis or treatment of thrombosis in adult patients with heparin-induced thrombocytopenia (HIT) ( 1.1 ) As an anticoagulant in adult patients with or at risk for HIT undergoing percutaneous coronary intervention (PCI) ( 1.2 ) 1.1 Heparin-Induced Thrombocytopenia Argatroban Injection is indicated for prophylaxis or treatment of thrombosis in adult patients with heparin-induced thrombocytopenia (HIT). 1.2 Percutaneous Coronary Intervention Argatroban Injection is indicated as an anticoagulant in adult patients with or at risk for HIT undergoing percutaneous coronary intervention (PCI).

2 DOSAGE AND ADMINISTRATION Argatroban Injection 250 mg/2.5 mL (100 mg/mL) must be diluted 100-fold by mixing with 0.9% Sodium Chloride Injection, 5% Dextrose Injection, or Lactated Ringer’s Injection to a final concentration of 1 mg/mL. ( 2.1 ) Argatroban Injection 50 mg/50 mL (1 mg/mL) is ready for intravenous infusion. Dilution is not required. ( 2.1 ) Heparin-Induced Thrombocytopenia The dose for heparin-induced thrombocytopenia without hepatic impairment is 2 mcg/kg/min administered as a continuous infusion. ( 2.2 ) Percutaneous Coronary Intervention The dose for patients with or at risk for heparin-induced thrombocytopenia undergoing percutaneous coronary intervention is started at 25 mcg/kg/min and a bolus of 350 mcg/kg administered via a large bore intravenous line over 3 to 5 minutes. ( 2.3 ) 2.1 Preparation for Intravenous Administration Argatroban Injection 250 mg/2.5 mL (100 mg/mL) must be diluted 100-fold prior to infusion. Argatroban should not be mixed with other drugs prior to dilution. Dilution is not required for Argatroban Injection 50 mg/50 mL (1 mg/mL). Argatroban Injection 250 mg/2.5 mL (100 mg/mL) Argatroban 250 mg/2.5 mL (100 mg/mL) should be diluted in 0.9% Sodium Chloride Injection, 5% Dextrose Injection, or Lactated Ringer’s Injection to a final concentration of 1 mg/mL. The contents of each 2.5-mL vial should be diluted 100-fold by mixing with 250 mL of diluent. Use 250 mg (2.5 mL) per 250 mL of diluent or 500 mg (5 mL) per 500 mL of diluent. The constituted solution must be mixed by repeated inversion of the diluent bag for 1 minute. Upon preparation, the solution may show slight but brief haziness due to the formation of microprecipitates that rapidly dissolve upon mixing. Use of diluent at room temperature is recommended. Colder temperatures can slow down the rate of dissolution of precipitates. The final solution must be clear before use. The pH of the intravenous solution prepared as recommended is 3.2 to 7.5. Solutions prepared as recommended are stable at controlled room temperature, 20º to 25ºC (68º to 77ºF) (see USP) in ambient indoor light for 24 hours; therefore, light-resistant measures such as foil protection for intravenous lines are unnecessary. Solutions are physically and chemically stable for up to 96 hours when protected from light and stored at controlled room temperature, 20º to 25ºC (68º to 77ºF) (see USP) or at refrigerated conditions, 5º±3ºC (41º±5ºF). Prepared solutions should not be exposed to direct sunlight. No significant potency losses have been noted following simulated delivery of the solution through intravenous tubing. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit. Argatroban Injection 50 mg/50 mL (1 mg/mL) Each 50 mL glass vial contains 50 mg argatroban (1 mg/mL); and, as supplied, is ready for intravenous infusion. Dilution is not required. Argatroban Injection is a clear, colorless to pale yellow solution. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit. Do not use if solution is cloudy, contains precipitates, or if the flip top cap is not intact. Vial may be inverted for use with a medical infusion set. 2.2 Dosing in Patients with Heparin-Induced Thrombocytopenia Initial Dosage Before administering argatroban, discontinue heparin therapy and obtain a baseline activated partial thromboplastin time (aPTT). The recommended initial dose of argatroban for adult patients without hepatic impairment is 2 mcg/kg/min, administered as a continuous infusion (see Table 1). Table 1 Recommended Doses and Infusion Rates for 2 mcg/kg/min Dose of Argatroban for Patients With HIT* and Without Hepatic Impairment (1 mg/mL Final Concentration) Body Weight (kg) Dose (mcg/min) Infusion Rate (mL/hr) 50 100 6 60 120 7 70 140 8 80 160 10 90 180 11 100 200 12 110 220 13 120 240 14 130 260 16 140 280 17 *with or without thrombosis Monitoring Therapy For use in HIT, therapy with Argatroban Injection is monitored using the aPTT with a target range of 1.5 to 3 times the initial baseline value (not to exceed 100 seconds). Tests of anticoagulant effects (including the aPTT) typically attain steady-state levels within 1 to 3 hours following initiation of Argatroban Injection. Check the aPTT 2 hours after initiation of therapy and after any dose change to confirm that the patient has attained the desired therapeutic range. Dosage Adjustment After the initiation of Argatroban Injection, adjust the dose (not to exceed 10 mcg/kg/min) as necessary to obtain a steady-state aPTT in the target range [see Clinical Studies (14.1) ]. 2.3 Dosing in Patients Undergoing Percutaneous Coronary Intervention Initial Dosage Initiate an infusion of Argatroban Injection at 25 mcg/kg/min and administer a bolus of 350 mcg/kg via a large bore intravenous line over 3 to 5 minutes (se

6 ADVERSE REACTIONS The following adverse reaction is also discussed in other sections of the labeling: Risk of Hemorrhage [see Warnings and Precautions (5.1) ] . HIT patients: The most common (>5%) adverse reactions were dyspnea, hypotension, fever, diarrhea, sepsis, and cardiac arrest. (6.1) PCI patients: The most common (>5%) adverse reactions were chest pain, hypotension, back pain, nausea, vomiting and headache. (6.1) To report SUSPECTED ADVERSE REACTIONS, contact Hikma Pharmaceuticals USA Inc. at 1-877-233-2001 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Adverse Reactions in Patients with HIT (With or Without Thrombosis) 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. The following safety information is based on all 568 patients treated with argatroban in Study 1 and Study 2. The safety profile of the patients from these studies is compared with that of 193 historical controls in which the adverse reactions were collected retrospectively. Adverse reactions are separated into hemorrhagic and non-hemorrhagic reactions. Major bleeding was defined as bleeding that was overt and associated with a hemoglobin decrease ≥ 2 g/dL, that led to a transfusion of ≥ 2 units, or that was intracranial, retroperitoneal, or into a major prosthetic joint. Minor bleeding was overt bleeding that did not meet the criteria for major bleeding. Table 4 gives an overview of the most frequently observed hemorrhagic reactions, presented separately by major and minor bleeding, sorted by decreasing occurrence among argatroban-treated patients with HIT (with or without thrombosis). Table 4 Major and Minor Hemorrhagic Adverse Reactions in Patients With HIT* Major Hemorrhagic Reactions a Argatroban-treated Patients (Study 1 and Study 2) (n = 568) % Historical Control c (n = 193) % Overall bleeding 5.3 6.7 Gastrointestinal 2.3 1.6 Genitourinary and hematuria 0.9 0.5 Decrease in hemoglobin and hematocrit 0.7 0 Multisystem hemorrhage and DIC 0.5 1 Limb and BKA stump 0.5 0 Intracranial hemorrhage 0 b 0.5 Minor Hemorrhagic Reactions a Argatroban-treated Patients (Study 1 and Study 2) (n = 568) % Historical Control c (n = 193) % Gastrointestinal 14.4 18.1 Genitourinary and hematuria 11.6 0.8 Decrease in hemoglobin and hematocrit 10.4 0 Groin 5.4 3.1 Hemoptysis 2.9 0.8 Brachial 2.4 0.8 * with or without thrombosis a) Patients may have experienced more than 1 adverse reaction. b) One patient experienced intracranial hemorrhage 4 days after discontinuation of argatroban and following therapy with urokinase and oral anticoagulation. c) The historical control group consisted of patients with a clinical diagnosis of HIT (with or without thrombosis) that were considered eligible by an independent medical panel. DIC = disseminated intravascular coagulation. BKA = below the knee amputation. Table 5 gives an overview of the most frequently observed non-hemorrhagic reactions sorted by decreasing frequency of occurrence (≥2%) among argatroban-treated HIT/HITTS patients. Table 5 Non-hemorrhagic Adverse Reactions in Patients a With HIT b Argatroban-treated Patients (Study 1 and Study 2) (n = 568) % Historical Control c (n = 193) % Dyspnea 8.1 8.8 Hypotension 7.2 2.6 Fever 6.9 2.1 Diarrhea 6.2 1.6 Sepsis 6.0 12.4 Cardiac arrest 5.8 3.1 Nausea 4.8 0.5 Ventricular tachycardia 4.8 3.1 Pain 4.6 3.1 Urinary tract infection 4.6 5.2 Vomiting 4.2 0 Infection 3.7 3.6 Pneumonia 3.3 9.3 Atrial fibrillation 3.0 11.4 Coughing 2.8 1.6 Abnormal renal function 2.8 4.7 Abdominal pain 2.6 1.6 Cerebrovascular disorder 2.3 4.1 a) Patients may have experienced more than 1 adverse reaction. b) With or without thrombosis c) The historical control group consisted of patients with a clinical diagnosis of HIT (with or without thrombosis) that were considered eligible by an independent medical panel. Adverse Reactions in Patients with or at Risk for HIT Undergoing PCI The following safety information is based on 91 patients initially treated with argatroban and 21 patients subsequently re-exposed to argatroban for a total of 112 PCIs with argatroban anticoagulation. Adverse reactions are separated into hemorrhagic (Table 6) and non-hemorrhagic (Table 7) reactions. Major bleeding was defined as bleeding that was overt and associated with a hemoglobin decrease ≥5 g/dL, that led to a transfusion of ≥2 units, or that was intracranial, retroperitoneal, or into a major prosthetic joint. The rate of major bleeding events in patients treated with argatroban in the PCI trials was 1.8%. Table 6 Major and Minor Hemorrhagic Adverse Reactions in Patients With HIT Undergoing PCI Major Hemorrhagic Reactions a Argatroban-treated Patients (n = 112) b % Retroperitoneal 0.9 Gastrointestinal 0.9 Intracranial 0 Minor Hemorrhagic Reactions a Argatroban-t

7 DRUG INTERACTIONS Heparin: Allow sufficient time for heparin’s effect on activated partial thromboplastin time (aPTT) to decrease before initiating Argatroban Injection therapy. ( 7.1 ) Warfarin: Concomitant use results in increased prolongation of PT and INR. ( 7.2 ) Thrombolytic agents or glycoprotein IIb/IIIa antagonists: Safety and effectiveness of concomitant use with argatroban have not been established. ( 7.4 , 7.5 ) 7.1 Heparin If argatroban is to be initiated after cessation of heparin therapy, allow sufficient time for heparin’s effect on the aPTT to decrease prior to initiation of argatroban therapy. 7.2 Oral Anticoagulant Agents Pharmacokinetic drug-drug interactions between argatroban and warfarin (7.5 mg single oral dose) have not been demonstrated. However, the concomitant use of argatroban and warfarin (5 to 7.5 mg initial oral dose, followed by 2.5 to 6 mg/day orally for 6 to 10 days) results in prolongation of the prothrombin time (PT) and International Normalized Ratio (INR) [see Dosage and Administration (2.5 ) and Clinical Pharmacology (12.2) ]. 7.3 Aspirin/Acetaminophen No drug-drug interactions have been demonstrated between argatroban and concomitantly administered aspirin or acetaminophen [ see Clinical Pharmacology (12.3) ]. 7.4 Thrombolytic Agents The safety and effectiveness of argatroban with thrombolytic agents have not been established [ see Adverse Reactions (6.1) ] . 7.5 Glycoprotein IIb/IIIa Antagonists The safety and effectiveness of argatroban with glycoprotein IIb/IIIa antagonists have not been established.