title: Drug-induced thrombocytopenia for the hospitalist physician with a focus on heparin-induced thrombocytopenia.
abstract: Acute thrombocytopenia occurs commonly in hospitalized patients. For most, the etiology of an acutely declining platelet count is obvious and includes sepsis with disseminated intravascular coagulation, large-volume crystalloid infusion, or the administration of cytotoxic therapies, such as chemotherapeutic agents. For others, however, the etiology may be less apparent. In these cases, drug-induced thrombocytopenia (DIT), including heparin-induced thrombocytopenia (HIT), must be a diagnostic consideration. The approach to the hospitalized patient with thrombocytopenia, without an obvious cause, includes a careful medication history to identify potential culprits, such as glycoprotein IIb/IIIa inhibitors, vancomycin, linezolid, beta-lactam antibiotics, quinine, antiepileptic drugs, or heparin/low-molecular-weight heparin. Usually, discontinuation of the offending medication is all that is necessary for resolution of thrombocytopenia. Heparin-induced thrombocytopenia, however, is an exception to this general rule given its unique pathogenesis and propensity for thrombotic complications and death. Differentiating between HIT and DIT due to nonheparin medications may prove challenging. Through a careful clinical assessment, consideration of the pre-test probability for HIT, and the thoughtful application of laboratory testing, HIT can be accurately diagnosed. Because patients with HIT have a high risk of thrombosis and bleeding is uncommon, the prompt initiation of an alternative anticoagulant (e.g., a direct thrombin inhibitor) is warranted in these patients.
authors.affiliation: Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT 84112, USA. matthew.rondina@hsc.utah.edu
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Rondina
authors.forename: Amanda
authors.initials: A
authors.lastname: Walker
authors.forename: Robert C
authors.initials: RC
authors.lastname: Pendleton
mesh_terms: D000208:Acute Disease; D000465:Algorithms; D000900:Anti-Bacterial Agents / Q000009:adverse effects; D000925:Anticoagulants / Q000009:adverse effects*; D000927:Anticonvulsants / Q000009:adverse effects; D015984:Causality; D003663:Decision Trees; D003937:Diagnosis, Differential; D006493:Heparin / Q000009:adverse effects*; D020445:Hospitalists / Q000379:methods; D006801:Humans; D008487:Medical History Taking; D010976:Platelet Count; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors; D011802:Quinidine / Q000009:adverse effects; D011803:Quinine / Q000009:adverse effects; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology / Q000628:therapy; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D000925:Anticoagulants; D000927:Anticonvulsants; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D006493:Heparin; D011803:Quinine; D011802:Quinidine
references.citation: Expert Opin Pharmacother. 2003 Jun;4(6):919-40
references.pmid: 12783589
references.citation: Blood Coagul Fibrinolysis. 2008 Sep;19(6):471-5
references.pmid: 18685428
references.citation: Br J Haematol. 1981 Dec;49(4):531-40
references.pmid: 7317283
references.citation: DICP. 1990 Jul-Aug;24(7-8):693-5
references.pmid: 1695793
references.citation: Drug Saf. 1997 Nov;17(5):325-41
references.pmid: 9391776
references.citation: Aust N Z J Med. 1986 Oct;16(5):715-6
references.pmid: 3469974
references.citation: Drugs. 2008;68(7):901-12
references.pmid: 18457458
references.citation: Am J Med. 2008 Jul;121(7):632-6
references.pmid: 18589060
references.citation: Pharmacotherapy. 2006 Oct;26(10):1438-45
references.pmid: 16999654
references.citation: Clin Ther. 2009 Oct;31(10):2126-33
references.pmid: 19922883
references.citation: Arch Intern Med. 2008 Jan 14;168(1):94-102
references.pmid: 18195201
references.citation: Chest. 2005 Feb;127(2 Suppl):53S-59S
references.pmid: 15706031
references.citation: Pharmacotherapy. 2000 Mar;20(3):292-307
references.pmid: 10730685
references.citation: Eur J Haematol. 1997 Apr;58(4):279-85
references.pmid: 9186540
references.citation: J Thromb Haemost. 2007 Jul;5(7):1373-9
references.pmid: 17362241
references.citation: Curr Hematol Rep. 2003 Mar;2(2):148-57
references.pmid: 12901146
references.citation: J Thromb Haemost. 2006 Apr;4(4):759-65
references.pmid: 16634744
references.citation: Circulation. 2003 Oct 28;108(17):2062-5
references.pmid: 14568897
references.citation: Antimicrob Agents Chemother. 2002 Aug;46(8):2723-6
references.pmid: 12121967
references.citation: Chest. 2008 Jun;133(6 Suppl):340S-380S
references.pmid: 18574270
references.citation: Arch Intern Med. 2003 Nov 10;163(20):2518-24
references.pmid: 14609790
references.citation: Arch Pathol Lab Med. 2009 Feb;133(2):309-14
references.pmid: 19195976
references.citation: Ann Intern Med. 1998 Dec 1;129(11):886-90
references.pmid: 9867731
references.citation: Drug Saf. 2004;27(15):1243-52
references.pmid: 15588119
references.citation: Am J Med. 1996 Nov;101(5):502-7
references.pmid: 8948273
references.citation: Hematol Oncol Clin North Am. 2007 Aug;21(4):685-96, vi
references.pmid: 17666285
references.citation: Curr Opin Pulm Med. 2008 Sep;14(5):397-402
references.pmid: 18664968
references.citation: Am J Hematol. 1999 Jul;61(3):205-8
references.pmid: 10398314
references.citation: N Engl J Med. 2007 Mar 1;356(9):904-10
references.pmid: 17329697
references.citation: Blood. 1991 Jan 15;77(2):306-10
references.pmid: 1898704
references.citation: Blood. 2002 Sep 15;100(6):2071-6
references.pmid: 12200368
references.citation: Thromb Res. 2008;123(1):137-45
references.pmid: 18582919
references.citation: Hematology Am Soc Hematol Educ Program. 2009;:153-8
references.pmid: 20008194
references.citation: Circulation. 2005 May 24;111(20):2671-83
references.pmid: 15911718
references.citation: Am J Hematol. 1996 Jun;52(2):90-5
references.pmid: 8638647
references.citation: J Thromb Haemost. 2009 Jun;7(6):911-8
references.pmid: 19344362
references.citation: Ann Intern Med. 1984 Apr;100(4):535-40
references.pmid: 6367579
references.citation: N Engl J Med. 2007 Jun 21;356(25):2653-5; discussion 2653-5
references.pmid: 17582083
references.citation: Circulation. 2009 May 12;119(18):2454-62
references.pmid: 19398666
references.citation: Eur J Haematol. 2005 Aug;75(2):101-5
references.pmid: 16000126
references.citation: Semin Thromb Hemost. 2004 Feb;30 Suppl 1:69-80
references.pmid: 15085468
references.citation: Am J Cardiol. 2004 Apr 15;93(8):979-84
references.pmid: 15081439
references.citation: Arch Intern Med. 2004 Jan 26;164(2):218-20
references.pmid: 14744847
references.citation: Blood. 2006 Mar 15;107(6):2346-53
references.pmid: 16304054
references.citation: Transfusion. 2008 Oct;48(10):2128-32
references.pmid: 18657085
references.citation: J Thromb Haemost. 2009 Jul;7 Suppl 1:9-12
references.pmid: 19630757
references.citation: Chest. 2008 Sep;134(3):568-573
references.pmid: 18490399
references.citation: Thromb Haemost. 2008 Oct;100(4):678-84
references.pmid: 18841292
references.citation: Clin Infect Dis. 2006 Jan 1;42(1):66-72
references.pmid: 16323094
references.citation: Ann Med Interne (Paris). 1994;145(5):357-60
references.pmid: 7985949
references.citation: Chest. 2009 Jun;135(6):1651-1664
references.pmid: 19497901
references.citation: Ann Thorac Surg. 2003 Aug;76(2):638-48
references.pmid: 12902132
references.citation: Mayo Clin Proc. 2001 Aug;76(8):863-4
references.pmid: 11499830
references.citation: Semin Hematol. 1998 Oct;35(4 Suppl 5):9-16; discussion 35-6
references.pmid: 9855179
references.citation: Ann Intern Med. 1990 Feb 15;112(4):308-9
references.pmid: 2297210