Clopidogrel desensitization: case report and review of published protocols

Area of Science:

• Cardiology
• Pharmacology
• Immunology

Background:

• Clopidogrel, a thienopyridine antiplatelet, is crucial for cardiovascular disease prevention.
• Hypersensitivity reactions, including cutaneous reactions and angioedema, are rare but serious adverse effects.
• Alternative antiplatelets like ticlopidine and cilostazol have limitations and potential cross-reactivity or limited data.

Observation:

• A 58-year-old patient developed a diffuse rash after starting clopidogrel post-drug-eluting stent placement.
• Clopidogrel was discontinued, leading to rash resolution, but ticlopidine was later stopped due to severe diarrhea.
• The patient had an implanted stent, necessitating continued antiplatelet therapy.

Findings:

• The patient's rash was determined to be a probable adverse reaction to clopidogrel (Naranjo scale score of 8).
• An 8-hour clopidogrel desensitization protocol was successfully implemented.
• The patient tolerated clopidogrel for a year post-desensitization without recurrence of the rash.

Implications:

• Clopidogrel desensitization protocols can be a safe and effective therapeutic option for patients with isolated cutaneous hypersensitivity reactions.
• This strategy allows for continued clopidogrel use, mitigating thrombosis risk in stented patients.
• Desensitization provides an alternative when other thienopyridines or agents like cilostazol are unsuitable.