argatroban

Argatroban is a direct thrombin inhibitor indicated: For prophylaxis or treatment of thrombosis in adult patients with heparin-induced thrombocytopenia (HIT) As an anticoagulant in adult patients with or at risk for HIT undergoing percutaneous coronary intervention (PCI) 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).

Argatroban 125 mg in 125 mL aqueous sodium chloride solution (1 mg/mL) is intended for administration to adult patients Discontinue all parenteral anticoagulants before administering Argatroban Injection Adjust dosing in patients with HIT who have moderate or severe hepatic impairment Heparin-Induced Thrombocytopenia The dose for heparin-induced thrombocytopenia without hepatic impairment is 2 mcg/kg/min administered as a continuous infusion Discontinue heparin therapy and obtain a baseline aPTT before administering Argatroban After the initial dose of Argatroban, the dose can be adjusted as clinically indicated 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 Activated clotting time (ACT) should be checked 5 to 10 minutes after the bolus dose is completed. The procedure may proceed if the ACT is greater than 300 seconds Monitoring therapy and dosage adjustments recommendations should be followed See special dosing recommendations for hepatic and renal impaired patients 2.1 Intravenous Administration Each 125 mL glass vial contains 125 mg of 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 the solution is cloudy, contains precipitates, or if the flip-off seal is not intact. 2.2 Dosing in Patients with Heparin-Induced Thrombocytopenia Initial Dosage Before administering argatroban, discontinue heparin therapy and obtain a baseline 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 1 and Without Hepatic Impairment (1 mg/mL 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 1. 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 ] . 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 (see Table 2 ). Check an activated clotting time (ACT) 5 to 10 minutes after the bolus dose is completed. The PCI procedure may proceed if the ACT is greater than 300 seconds. Dosage Adjustment If the ACT is less than 300 seconds, an additional intravenous bolus dose of 150 mcg/kg should be administered, the infusion dose increased to 30 mcg/kg/min, and the ACT checked 5 to 10 minutes later (see Table 2 ). If the ACT is greater than 450 seconds, decrease the infusion rate to 15 mcg/kg/min, and check the ACT 5 to 10 minutes later ( Table 3 ). Continue titrating the dose until a therapeutic ACT (between 300 and 450 seconds) has been achieved; continue the same infusion rate for the duration of the PCI procedure. In case of dissection, impending abrupt closure, thrombus formation during the procedure, or inability to achieve or maintain an ACT over 300 seconds, additional bolus doses of 150 mcg/kg may be administered and the infusion dose increased to 40 mcg/kg/min. Check the ACT after each additional bolus or change in the rate of infusion. Table 2. Recommended Starting and Maintenance Doses (Within the Target ACT Range) of Argatroban Injection in Patients Undergoing PCI Without Hepatic Impairment (1 mg/mL Concentration) Body Weight (kg) Starting Bolus Dose (350 mcg/kg) Starting and Maintenance Continuous Infusion Dosing For ACT 300 to 450 seconds 25 mcg/kg/min Bolus Dose (mcg) Bolus Volume (mL) Continuous Infusion Dose (mcg/min) Continuous Infusion Rate (mL/hr) 50 17,500 18 1,250 75 60 21,000 21 1,500 90 70 24,500 25 1,750 105 80 28,000 28 2,000 120 90 31,500 32 2,250 135 100 35,000 35 2,500 150 110 38,500 39 2,750 165 120 42,000 42 3,000 180 130 45,500 46 3,250 195 140 49,000 49 3,500 210 NOTE: 1 mg = 1,000 mcg; 1 kg = 2.2 lbs Table 3. Recommended Dose Adjustments of Argatroban Injection for Patients Outside of ACT Target Range Undergoing PCI Without Hepatic Impairment (1 mg/mL Concentration) Body Weight (kg) If ACT Less than 300 seconds Dosage Adjustment 1 30 mcg/kg/min If ACT Greater than 450 seconds Dosage Adjustment 2 15 mcg/kg/min Additional Bolus Dose (mcg) Bolus Volume (mL) Continuous Infusion Dose (mcg/min) Continuous Infusion Rate (mL/hr) Continuous Infusion Dose (mcg/min) Continuous Infusion Rate (mL/hr) 50 7,500 8 1,500 90 750 45 60 9,000 9 1,800 108 900 54 70 10,500 11 2,100 126 1,050 63 80 12,000 12 2,400 144 1,200 72 90 13,500 14 2,700 162 1,350 81 100 15,000 15 3,000 180 1,500 90 110 16,500 17 3,300 198 1,650 99 120 18,000 18 3,600 216 1,800 108 130 19,500 20 3,900 234 1,950 117 140 21,000 21 4,200 252 2,100 126 NOTE: 1 mg = 1,000 mcg; 1 kg = 2.2 lbs 1. Additional intravenous bolus dose of 150 mcg/kg should be administered if ACT less than 300 seconds. 2. No bolus dose is given if ACT greater than 450 seconds Monitoring Therapy For use in PCI, therapy with Argatroban Injection is monitored using ACT. Obtain ACTs before dosing, 5 to 10 minutes after bolus dosing, following adjustments in the infusion rate, and at the end of the PCI procedure. Obtain additional ACTs every 20 to 30 minutes during a prolonged procedure. Continued Anticoagulation after PCI If a patient requires anticoagulation after the procedure, Argatroban Injection may be continued, but at a rate of 2 mcg/kg/min and adjusted as needed to maintain the aPTT in the desired range [see Dosage and Administration ] . 2.4 Dosing in Patients with Hepatic Impairment Initial Dosage For adult patients with HIT and moderate or severe hepatic impairment (based on Child-Pugh classification), an initial dose of 0.5 mcg/kg/min is recommended, based on the approximately 4-fold decrease in argatroban clearance relative to those with normal hepatic function. Monitor the aPTT closely, and adjust the dosage as clinically indicated. Monitoring Therapy Achievement of steady state aPTT levels may take longer and require more dose adjustments in patients with hepatic impairment compared to patients with normal hepatic function. For patients with hepatic impairment undergoing PCI and who have HIT or are at risk for HIT, carefully titrate argatroban until the desired level of anticoagulation is achieved. Use of Argatroban in PCI patients with clinically significant hepatic disease or AST/ALT levels ≥3 times the upper limit of normal should be avoided [see Warnings and Precautions ] . 2.5 Conversion to Oral Anticoagulant Therapy Initiating Oral Anticoagulant Therapy When converting patients from Argatroban to oral anticoagulant therapy, consider the potential for combined effects on International Normalized Ratio (INR). To avoid prothrombotic effects and to ensure continuous anticoagulation when initiating warfarin, overlap Argatroban Injection and warfarin therapy. There are insufficient data available to recommend the duration of the overlap. Initiate therapy using the expected daily dose of warfarin. A loading dose of warfarin should not be used. The relationship between INR and bleeding risk is altered when argatroban and warfarin are co-administered. The combination of argatroban and warfarin does not cause further reduction in the vitamin K–dependent factor Xa activity than that which is seen with warfarin alone. The relationship between INR obtained on combined therapy and INR obtained on warfarin alone is dependent on both the dose of argatroban and the thromboplastin reagent used. The INR value on warfarin alone (INRW) can be calculated from the INR value on combination argatroban and warfarin therapy [see Drug Interactions and Clinical Pharmacology ] . Co-Administration of Warfarin and Argatroban Injection at Doses Up to 2 mcg/kg/min Measure INR daily while Argatroban Injection and warfarin are co-administered. In general, with doses of Argatroban Injection up to 2 mcg/kg/min, Argatroban Injection can be discontinued when the INR is >4 on combined therapy. After Argatroban Injection is discontinued, repeat the INR measurement in 4 to 6 hours. If the repeat INR is below the desired therapeutic range, resume the infusion of Argatroban Injection and repeat the procedure daily until the desired therapeutic range on warfarin alone is reached. Co-Administration of Warfarin and Argatroban Injection at Doses Greater than 2 mcg/kg/min For doses greater than 2 mcg/kg/min, the relationship of INR between warfarin alone to the INR on warfarin plus argatroban is less predictable. In this case, in order to predict the INR on warfarin alone, temporarily reduce the dose of Argatroban Injection to a dose of 2 mcg/kg/min. Repeat the INR on Argatroban Injection and warfarin 4 to 6 hours after reduction of the Argatroban Injection dose and follow the process outlined above for administering Argatroban Injection at doses up to 2 mcg/kg/min.

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.

The following adverse reaction is also discussed in other sections of the labeling:

• Risk of Hemorrhage [see Warnings and Precautions ] . HIT patients: The most common (> 5%) adverse reactions were dyspnea, hypotension, fever, diarrhea, sepsis, and cardiac arrest PCI patients: The most common (> 5%) adverse reactions were chest pain, hypotension, back pain, nausea, vomiting and headache To report SUSPECTED ADVERSE REACTIONS, contact Gland Pharma at 866-770-7144 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 events, 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 1 Major Hemorrhagic Reactions 2 Argatroban- Treated Patients (Study 1 and Study 2) (n = 568) % Historical Control 3 (n = 193) % Overall bleeding 5.3

Gastrointestinal 2.3

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 4

Minor Hemorrhagic Reactions 2 Gastrointestinal 14.4

Genitourinary and hematuria 11.6

Decrease in hemoglobin and hematocrit 10.4 0 Groin 5.4

Hemoptysis 2.9

Brachial 2.4 0.8 1. with or without thrombosis 2.

Patients may have experienced more than 1 adverse reaction. 3. 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. 4. One patient experienced intracranial hemorrhage 4 days after discontinuation of argatroban and following therapy with urokinase and oral anticoagulation. 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 1 With HIT 2 Argatroban-Treated Patients (Study 1 and Study 2) (n = 568) % Historical Control 3 (n = 193) % Dyspnea 8.1

Hypotension 7.2

Fever 6.9

Diarrhea 6.2

Sepsis 6.0

Cardiac arrest 5.8

Nausea 4.8

Ventricular tachycardia 4.8

Pain 4.6

Urinary tract infection 4.6

Vomiting 4.2 0 Infection 3.7

Pneumonia 3.3

Atrial fibrillation 3.0

Coughing 2.8

Abnormal renal function 2.8

Abdominal pain 2.6

Cerebrovascular disorder 2.3 4.1 1.

Patients may have experienced more than 1 adverse reaction. 2. with or without thrombosis 3. 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 Patients 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 1 Argatroban-Treated Patients (n = 112) 2 % Retroperitoneal

Gastrointestinal

0.9 Intracranial 0 Minor Hemorrhagic Reactions 1 Argatroban-Treated Patients (n = 112) 2 % Groin (bleeding or hematoma)

Gastrointestinal (includes hematemesis)

Genitourinary (includes hematuria)

Decrease in hemoglobin and/or hematocrit

CABG (coronary arteries)

Access site

Hemoptysis

Other 0.9 1.

Patients may have experienced more than 1 adverse reaction. 2. 91 patients who underwent 112 interventions. Table 7 gives an overview of the most frequently observed non-hemorrhagic reactions (>2%), sorted by decreasing frequency of occurrence among argatroban-treated PCI patients. Table 7. Non-hemorrhagic Adverse Reaction 1 in Patients With HIT Undergoing PCI Argatroban Procedures 1 (n = 112) 2 % Chest pain

Hypotension

Back pain

Nausea

Vomiting

Headache

Bradycardia

Abdominal pain

Fever

Myocardial infarction 3.6 1.

Patients may have experienced more than 1 adverse reaction. 2. 91 patients who underwent 112 interventions. There were 22 serious adverse reactions in 17 PCI patients (19.6% in 112 interventions). Table 8 lists the serious adverse reactions occurring in argatroban-treated patients with or at risk for HIT undergoing PCI. Table 8. Serious Adverse Reactions in Patients With HIT Undergoing PCI 1 Coded Term Argatroban Procedures 2 (n = 112) Myocardial infarction 4 (3.5%) Angina pectoris 2 (1.8%) Coronary thrombosis 2 (1.8%) Myocardial ischemia 2 (1.8%) Occlusion coronary 2 (1.8%) Chest pain 1 (0.9%) Fever 1 (0.9%) Retroperitoneal hemorrhage 1 (0.9%) Aortic stenosis 1 (0.9%) Arterial thrombosis 1 (0.9%) Gastrointestinal hemorrhage 1 (0.9 %) Gastrointestinal disorder (GERD) 1 (0.9%) Cerebrovascular disorder 1 (0.9%) Lung edema 1 (0.9%) Vascular disorder 1 (0.9%) 1. Individual reactions may also have been reported elsewhere (see Table 6 and 7 ). 2. 91 patients underwent 112 procedures. Some patients may have experienced more than 1 reaction. Intracranial Bleeding in Other Populations Increased risks for intracranial bleeding have been observed in investigational studies of argatroban for other uses. In a study of patients with acute myocardial infarction receiving both argatroban and thrombolytic therapy (streptokinase or tissue plasminogen activator), the overall frequency of intracranial bleeding was 1% (8 out of 810 patients). Intracranial bleeding was not observed in 317 subjects or patients who did not receive concomitant thrombolysis [see Drug Interactions ] . The safety and effectiveness of argatroban for cardiac indications other than PCI in patients with HIT have not been established. Intracranial bleeding was also observed in a prospective, placebo-controlled study of argatroban in patients who had onset of acute stroke within 12 hours of study entry. Symptomatic intracranial hemorrhage was reported in 5 of 117 patients (4.3%) who received argatroban at 1 to 3 mcg/kg/min and in none of the 54 patients who received placebo. Asymptomatic intracranial hemorrhage occurred in 5 (4.3%) and 2 (3.7%) of the patients, respectively. Allergic Reactions One hundred fifty-six allergic reactions or suspected allergic reactions were observed in 1,127 individuals who were treated with argatroban in clinical pharmacology studies or for various clinical indications. About 95% (148/156) of these reactions occurred in patients who concomitantly received thrombolytic therapy (e.g., streptokinase) or contrast media. Allergic reactions or suspected allergic reactions in populations other than patients with HIT (with or without thrombosis) include (in descending order of frequency):

• Airway reactions (coughing, dyspnea): 10% or more
• Skin reactions (rash, bullous eruption): 1 to <10%
• General reactions (vasodilation): 1 to 10% Limited data are available on the potential formation of drug-related antibodies. Plasma from 12 healthy volunteers treated with argatroban over 6 days showed no evidence of neutralizing antibodies. No loss of anticoagulant activity was noted with repeated administration of argatroban to more than 40 patients.

Heparin: Allow sufficient time for heparin’s effect on aPTT to decrease before initiating Argatroban Injection therapy Warfarin: Concomitant use results in increased prolongation of PT and INR Thrombolytic agents or glycoprotein IIb/IIIa antagonists: Safety and effectiveness of concomitant use with argatroban have not been established 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 and Clinical Pharmacology ] . 7.3 Aspirin/Acetaminophen No drug-drug interactions have been demonstrated between argatroban and concomitantly administered aspirin or acetaminophen [see Clinical Pharmacology ] . 7.4 Thrombolytic Agents The safety and effectiveness of argatroban with thrombolytic agents have not been established [see Adverse Reactions ] . 7.5 Glycoprotein IIb/IIIa Antagonists The safety and effectiveness of argatroban with glycoprotein IIb/IIIa antagonists have not been established.

Lactation: Discontinue nursing or drug, taking into account the importance of the drug to the mother Pediatric Use: Safety and effectiveness have not been established 8.1 Pregnancy Risk Summary Limited data from published literature and postmarketing reports do not suggest an association between argatroban and adverse fetal outcomes. There are risks to the mother associated with untreated thrombosis in pregnancy and a risk of hemorrhage in the mother and fetus associated with the use of anticoagulants ( see Clinical Considerations ). In animal reproduction studies, there was no evidence of adverse developmental outcomes with intravenous administration of argatroban during organogenesis in rats and rabbits at doses up to 0.3 and 0.2-times, respectively, the maximum recommended human dose (MHRD) ( see Data ). The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. 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 Disease-Associated Maternal and/or Embryo/Fetal Risk Pregnancy confers an increased risk for thromboembolism that is higher for women with underlying thromboembolic disease and certain high risk pregnancy conditions. Published data describe that women with a previous history of venous thrombosis are at high risk for recurrence during pregnancy. Fetal/Neonatal Adverse Reactions Use of anticoagulants, including argatroban, may increase the risk of bleeding in the fetus and neonate. Monitor neonates for bleeding [see Warnings and Precautions ]. Labor or Delivery All patients receiving anticoagulants, including pregnant women, are at risk for bleeding. Pregnant women receiving argatroban should be carefully monitored for evidence of excessive bleeding or unexpected changes in coagulation parameters [see Warnings and Precautions ]. Data Animal Data Developmental studies performed in rats with argatroban at intravenous doses up to 27 mg/kg/day (0.3 times the maximum recommended human dose, based on body surface area) and in rabbits at intravenous doses up to 10.8 mg/kg/day (0.2 times the maximum recommended human dose, based on body surface area) have revealed no evidence of harm to the fetus. 8.2 Lactation There are no data on the presence of argatroban in human milk, or its effects on milk production. Argatroban is detected in rat milk. The developmental and health benefits of breastfeeding should be considered along with the mother’s need for Argatroban and any potential adverse effects on the breastfed child from Argatroban or from the underlying maternal condition. 8.4 Pediatric Use Safety and effectiveness have not been established in pediatric patients. Argatroban was studied among 18 seriously ill pediatric patients who required an alternative to heparin anticoagulation. Most patients were diagnosed with HIT or suspected HIT. Age ranges of patients were 100 seconds for seriously ill pediatric patients with HIT/HITTS who require an alternative to heparin suggested the following:

• For patients with normal hepatic function, a starting infusion rate of 0.75 mcg/kg/min may have comparable aPTT responses as a starting dose of 2 mcg/kg/min in healthy adults. Additionally, based on an evaluation of aPTT every two hours, increasing the dosage by 0.1 to 0.25 mcg/kg/min could achieve additional aPTT responses.
• For patients with hepatic impairment a starting infusion rate of 0.2 mcg/kg/min with increasing dosing by increments of 0.05 mcg/kg/min may have comparable argatroban exposure as expected with adult doses. The safety and effectiveness of argatroban with the above dosing have not been adequately assessed in pediatric patients and the safety and effectiveness of argatroban is not established in pediatric patients. In addition, the described dosage did not take into account multiple factors that could affect the dosage such as current aPTT, target aPTT, and the clinical status of the patient. 8.5 Geriatric Use Of the total number of subjects in clinical studies of argatroban, 35% were 65 and over. In the clinical studies of adult patients with HIT (with or without thrombosis), the effectiveness of argatroban was not affected by age. No trends were observed across age groups for both aPTT and the ACT. The safety analysis did suggest that older patients tended to have an increased risk of events compared to younger patients; however, older patients had increased underlying conditions, which may predispose them to adverse reactions. The studies were not sized appropriately to detect differences in safety between age groups. 8.6 Hepatic Impairment Dose reduction and careful titration are required when administering argatroban to patients with hepatic impairment. Reversal of anticoagulation effect may be prolonged in this population [see Dosage and Administration , Warnings and Precautions , Clinical Pharmacology ] .