Over 90 million patients have been prescribed clopidogrel since its US FDA approval in 1997. Clopidogrel hypersensitivity affects up to 6% of patients, most commonly in the form of a pruritic rash. Symptoms are severe enough to result in drug discontinuation in 1.5% of patients. Premature discontinuation of clopidogrel is problematic following percutaneous coronary intervention because of the risk of stent thrombosis leading to myocardial infarction and death. Accordingly, the management of patients with clopidogrel hypersensitivity is of significant clinical importance. Conventional clopidogrel desensitization protocols, while successful in most patients, employ a washout period off medication to enable accurate detection of a reaction during the desensitization. However, interruption of therapy is potentially hazardous in patients with recent stent placement. Our clinical experience demonstrates that clopidogrel hypersensitivity can be successfully treated without drug interruption using short-course corticosteroids and antihistamines to enable the development of physiologic tolerance while the medication is continued. The role of newer agents, such as prasugrel, as surrogate therapy in patients with clopidogrel hypersensitivity is yet to be defined.
Campbell, Kimberly L; Cohn, John R; and Savage, Michael P, "Clopidogrel hypersensitivity: clinical challenges and options for management." (2010). Division of Cardiology Faculty Papers. Paper 13.