Thrombotic Thrombocytopenic Purpura Associated with Clopidogrel

Abstract

Thrombotic thrombocytopenic purpura can occur after the initiation of clopidogrel therapy, often within the first two weeks of treatment. Physicians should be aware of the possibility of this syndrome when initiating clopidogrel treatment.

Thrombocytopenic conditions—autoimmunity and hypercoagulability: Commonalities and differences in ITP, TTP, HIT, and APS

“…Tsai and Lian [16] described IgG and IgM inhibitory antibodies against ADAMTS13 activity in 50-80% of patients with acquired TTP [15,16]. Antibodies with similar activity have also been described in patients with TTP associated with ticlopidine or clopidogrel use [18,19]. Some patients with acquired TTP have unusual large multimers of vWf, in the absence of severely reduced levels of metalloprotease activity [20].…”

The Evaluation of the Renal Transplant Candidates: Clinical Practice Guidelines

“…Indeed, there is at least one multicenter, randomized, controlled trial in non-transplant recipients suggesting that ticlopidine reduces the incidence of recurrence in patients with TTP (356). On the other hand, a recent report in non-transplant patients suggested that clopidogrel bisulfate use is associated with an increased incidence of TTP (357). Thus, the role of specific antiplatelet agents in the prevention of recurrent HUS/ TTP is unclear.…”

Secondary stroke prevention: Review of clinical trials

“…60 Recent reports of clopidogrel-associated thrombotic thrombocytopenic purpura (at an estimated rate between 1 in 1,600 to 1 in 5,000) have led to the suggestion that platelet levels should be routinely monitored after initiating therapy. 61 In addition, a recent report has suggested that atorvastatin, a commonly used HMG-CoA inhibitor, may reduce the inhibition of platelet aggregation by clopidogrel, 62 although this view has been challenged. 63 An alternative approach to antiplatelet treatment involves combination therapy using two different agents with distinct modes of action.…”