Clopidogrel desensitization after drug-eluting stent placement.

OBJECTIVES We hypothesized that a standardized outpatient clopidogrel desensitization protocol would be safe and effective. BACKGROUND Adverse reactions to clopidogrel are not uncommon, and affected patients must switch to ticlopidine after drug-eluting stent placement, despite its more malignant side-effect profile, because of the risk of ischemic events associated with premature discontinuation of dual antiplatelet therapy. METHODS Patients with suspected clopidogrel sensitivity were treated with escalating doses of clopidogrel administered orally in solution until either a clinically significant reaction occurred or the full 75-mg tablet of clopidogrel was tolerated. Desensitization was performed on an outpatient basis except in cases in which the subjects were inpatients at the time of enrollment. Follow-up was performed at 2 to 4 weeks and 6 months after treatment. Successful desensitization was defined as the ability to take clopidogrel 75 mg daily without a mucocutaneous, bronchial, or anaphylactic response. RESULTS We enrolled 24 consecutive patients with suspected reactions to clopidogrel after DES implantation, 20 of whom were outpatients. During desensitization, allergic-type reactions occurred in 4 patients and angina occurred in 1 patient. Desensitization was acutely successful in all 24 patients, and by 6-month follow-up, 1 patient had persistent but improved pruritus controlled with oral antihistamines and 23 remained asymptomatic, with only 2 patients requiring repeat desensitization. CONCLUSIONS Clopidogrel desensitization is safe and effective, induces a sustained remission, and could be advantageous in treating outpatients who are at-risk for premature discontinuation of dual antiplatelet therapy.