title: Efficacy and safety of argatroban and bivalirudine in patients with suspected heparin-induced thrombocytopenia.
abstract: BACKGROUND
  Argatroban is the only commercially available Food and Drug Administration (FDA)-approved anticoagulant for managing heparin-induced thrombocytopenia (HIT). However, bivalirudin may be an attractive alternative.
  
  
  OBJECTIVE
  To assess the efficacy and safety of argatroban and bivalirudin in patients with suspected HIT.
  
  
  METHODS
  This single-center, retrospective analysis included patients who received argatroban or bivalirudin for at least 24 hours between January 1, 2000, and June 30, 2012. The primary end point assessed anticoagulation goals, specifically time to therapeutic activated partial thromboplastin time (aPTT) goal and percentage of aPTT values within therapeutic range. Secondary end points included new thromboembolic events, bleeding, and mortality.
  
  
  RESULTS
  Of the 68 patients who met the inclusion criteria, 48 received argatroban and 20 received bivalirudin. Baseline characteristics were similar between the 2 groups except for age, percentage of patients with liver dysfunction, aPTT immediately prior to drug initiation, and the serotonin release assay results. The mean ± SD times to reach therapeutic aPTT goal for argatroban and bivalirudin were 14 ± 15 and 7 ± 8 hours, respectively (P = 0.024). The mean ± SD percentage of aPTT values within therapeutic aPTT goal was 69% ± 23% for argatroban and 84% ± 18% for bivalirudin (P = 0.005). Rates of thromboembolic events were similar between the 2 groups, as were the rates of bleeding and all-cause mortality.
  
  
  CONCLUSIONS
  Bivalirudin appears to reach therapeutic aPTT goal faster with more aPTT values within therapeutic aPTT goal while achieving similar clinical outcomes. Although not approved by the FDA for managing HIT, bivalirudin may be an attractive alternative anticoagulant.
authors.affiliation: Quynh-Anh T. Vo, PharmD, BCPS, at time of writing, Pharmacy Practice Resident, Veterans Affairs Medical Center, San Francisco, CA.
authors.forename: Quynh-Anh T
authors.initials: QA
authors.lastname: Vo
authors.affiliation: Joyce K. Lin, PharmD, CACP, BCACP, Anticoagulation Clinical Pharmacist, Veterans Affairs Medical Center, San Francisco, CA; Assistant Clinical Professor of Pharmacy, University of California at San Francisco.
authors.forename: Joyce K
authors.initials: JK
authors.lastname: Lin
authors.affiliation: Lisa M. Tong, PharmD, CACP, Anticoagulation Clinical Pharmacist, Veterans Affairs Medical Center, San Francisco, CA; Associate Clinical Professor of Pharmacy, University of California at San Francisco Lisa.Tong@va.gov.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Tong
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001120:Arginine / Q000031:analogs & derivatives; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced / Q000188:drug therapy; D006493:Heparin / Q000009:adverse effects*; D006629:Hirudins; D006801:Humans; D008297:Male; D008875:Middle Aged; D010314:Partial Thromboplastin Time; D010446:Peptide Fragments / Q000627:therapeutic use*; D010875:Pipecolic Acids / Q000627:therapeutic use*; D011994:Recombinant Proteins / Q000627:therapeutic use; D012189:Retrospective Studies; D013449:Sulfonamides; D013921:Thrombocytopenia / Q000139:chemically induced / Q000188:drug therapy*
chemical_list: D000925:Anticoagulants; D006629:Hirudins; D010446:Peptide Fragments; D010875:Pipecolic Acids; D011994:Recombinant Proteins; D013449:Sulfonamides; D006493:Heparin; D001120:Arginine; C031942:argatroban; C074619:bivalirudin
keywords: anticoagulation; argatroban; bivalirudin; direct thrombin inhibitors; heparin-induced thrombocytopenia