Abstract 4453: Successful Treatment of Clopidogrel Hypersensitivity Without Drug Interruption
Premature discontinuation of dual antiplatelet therapy is an important predictor of stent thrombosis. Hypersensitivity affects 6% of patients treated with clopidogrel often resulting in drug discontinuation. Clopidogrel desensitization has been previously described utilizing a protocol of dose titration following a washout period to enable detection of reaction to desensitizing dose. This technique is problematic in patients with recently implanted stents since therapy interruption carries significant risk of stent thrombosis. The purpose of this study was to assess a strategy of clopidogrel hypersensitivity management without drug interruption utilizing corticosteroids and antihistamines to allow for development of physiologic tolerance. A retrospective analysis of clopidogrel hypersensitivity following stent placement was performed in patients treated from January 1, 2005 to April 30, 2008. The primary outcome was response of hypersensitivity symptoms to treatment regimen. Secondary outcomes included duration of clopidogrel therapy and recurrence of hypersensitivity reaction. The study population consisted of 20 patients (15 men and 5 women) with mean age 62 ± 9 years who underwent PCI and subsequently developed clopidogrel hypersensitivity at mean 6 ± 2 days of therapy. Indications for revascularization included STEMI (14%), acute coronary syndrome (43%), stable angina (5%), and positive stress test (38%). Patients received a mean of 2.2 stents, with drug eluting stents in 16 cases (76%). Treatment of clopidogrel hypersensitivity was successful in 17 of 20 patients (85%). Treatment regimens included corticosteroids (15) and antihistamines (17) with combination therapy in 11. Median duration of corticosteroid therapy was 6 days (range 6 –20). Mean duration of clopidogrel therapy was 257 ± 287 days with a median of 151 days. Two patients required repeat course of corticosteroids for relapse. Only 3 patients prematurely discontinued clopidogrel therapy due to persistent symptoms. In conclusion, patients who develop clopidogrel hypersensitivity after stent placement can be successfully treated with short-course corticosteroids and antihistamines without interruption of dual antiplatelet therapy.