Severe isolated thrombocytopenia after clopidogrel and pentoxifylline therapy: a case report

Abstract

IntroductionClopidogrel is frequently associated with thrombotic thrombocytopenic purpura, however this drug is rarely related to severe isolated thrombocytopenia. Pentoxifylline has previously been associated with thrombocytopenia only once. To the best of our knowledge, this is the first report of severe isolated thrombocytopenia after therapy with both clopidogrel and pentoxyfilline.Case presentationWe report the case of a 79-year-old Caucasian man who presented to our facility with intermittent claudication. He had obliterative arterial disease and started therapy with clopidogrel and pentoxifylline. His basal platelet count was 194 × 109 cells/L. At three days after the start of treatment, our patient had lower limb petechia and stopped taking clopidogrel and pentoxifylline. His platelet count lowered to 4 × 109 cells/L and our patient was admitted to hospital. Our patient had purpura with no other hemorrhages or splenomegaly. Results of a blood smear were normal, and a bone marrow study showed dysmegakaryopoiesis. Antiplatelet antibody test results were negative, as were all viral serology tests. Imaging study results were normal. Our patient was given immunoglobulin but there was no sustained platelet increase, so corticotherapy was started as the next treatment step. At five months after clopidogrel and pentoxifylline were discontinued, his platelet count continued increasing even after prednisolone was tapered.ConclusionsSevere isolated thrombocytopenia may appear as a side effect when using clopidogrel and pentoxifylline. These drugs are widely used by general physicians, internists, cardiologists and vascular surgeons. We hope this report will raise awareness of the need to monitor the platelet count in patients taking these drugs.

Pentoxifylline-Induced Thrombocytopenia

“…A literature search was conducted in the PubMed and Scopus databases using the key words “pentoxifylline” and “thrombocytopenia.” Two previous case reports were found. 6,7 Acharya and Nair described a patient who had received pentoxifylline 400 mg 3 times daily for a stasis ulcer and developed asymptomatic thrombocytopenia (platelets = 50 × 10 3 /µL). Platelets subsequently increased 48 hours after pentoxifylline discontinuation.…”

“…He received intravenous Ig without sustained platelet response and required corticosteroid therapy, which was tapered over 4 months with subsequent normalization of platelet counts. 7…”

“…His platelet levels remained depressed for several weeks and normalized almost 1 month after discontinuation of pentoxifylline and clopidogrel. 7 We report a case of pentoxifylline-induced thrombocytopenia in a 72-year-old male, which was reversible within 48 hours of discontinuation of therapy.…”

“…To the best of our knowledge, there have only been 2 case reports published on pentoxifylline-induced thrombocytopenia. 6,7 The first report published by Acharya and Nair in 1997 described an idiosyncratic episode of reversible pentoxifylline-induced thrombocytopenia, which was confirmed with reexposure. Platelet levels started recovering 48 hours after discontinuation of pentoxifylline.…”

Severe Isolated Thrombocytopenia Associated with the Use of Clopidogrel

“…However, the mechanism of isolated thrombocytopenia remains speculative. To the best of our knowledge, there are only four reports have involved this severe adverse effect induced by clopidogrel [2]- [5]. Here we report a case of a 73-year-old woman with unstable angina, treated with stent implantation, in whom acute stent thrombosis and twice thrombocytopenia were observed after PCI which is associated with clopidogrel-induced isolated thrombocytopenia.…”