Allergic reactions to clopidogrel soon after coronary stent implantation pose an important and challenging clinical problem. We describe a 44-year-old man who developed a diffuse maculopapular rash four days after initiation of clopidogrel with drug-eluting coronary stent placement. An initial treat-through strategy was unsuccessful due to patient intolerance to corticosteroids. Because of persistent hypersensitivity, clopidogrel was substituted with prasugrel which was continued successfully for one year without reaction. A systematic review of the literature was performed which identified 10 prior case reports of patients with clopidogrel hypersensitivity who were subsequently treated with prasugrel. Patient characteristics and clinical outcomes of these patients plus the current case were reviewed. There were 9 men and 2 women with ages from 44 to 76 years. All patients had undergone coronary stent procedures. Prasugrel was successfully used without cross-reactivity in 9 of the 11 patients (82%). Cross-reactivity was reported in two patients who developed hypersensitivity reactions to prasugrel similar to those experienced on clopidogrel. In conclusion, prasugrel can be used successfully in most patients with a history of clopidogrel hypersensitivity. However, potential cross-reactivity between these two thienopyridines may occur in some patients.
Keywords: Antiplatelet drugs; clopidogrel; hypersensitivity; prasugrel; thienopyridine.