Clopidogrel (Plavix) desensitization: A case series

Clopidogrel (Plavix) is a thiopyridine that inhibits the ADP-dependent pathway for platelet activation and has been shown in numerous trials to be effective for a wide variety of patients with cardiovascular disease, particularly those who have undergone coronary stent implantation and who present with acute coronary syndromes. Allergic rashes are one of the common side effects of clopidogrel, which leads to its discontinuation. Type I (Gell and Combs classification) allergic reactions to drugs may be amenable to drug desensitization, allowing safe and prolonged use of the drug. This case series describes a protocol for clopidogrel desensitization over an 8-hr period using 15 doubling doses of clopidogrel given by mouth to achieve a maintenance dose of 75 mg a day. This case series suggests that patients who have had type I drug allergy to clopidogrel may be rapidly desensitized using this protocol. Further studies enrolling a larger number of patients are indicated to confirm the safety and efficacy of this regimen.