Ticagrelor Use in a Patient With a Documented Clopidogrel Hypersensitivity

Area of Science:

• Cardiology
• Pharmacology

Background:

• Clopidogrel hypersensitivity reactions occur in approximately 1% of patients.
• Limited evidence exists for alternative antiplatelet agents in patients with clopidogrel allergy.
• Prasugrel, a thienopyridine, carries a theoretical risk of cross-reactivity and is not recommended for non-ST-segment elevation myocardial infarction (NSTEMI).

Purpose of the Study:

• To report the successful use of ticagrelor in a patient with a documented hypersensitivity reaction to clopidogrel.
• To evaluate ticagrelor as a potential alternative antiplatelet therapy in this specific clinical scenario.

Main Methods:

• A 64-year-old female patient with non-ST-segment elevation myocardial infarction (NSTEMI) and a history of clopidogrel hypersensitivity was medically managed.
• Ticagrelor was administered based on its distinct chemical structure and available evidence.
• Patient was monitored during hospitalization and at 2 and 4 weeks post-discharge for any adverse reactions.

Main Results:

• Ticagrelor was administered to the patient without any hypersensitivity reaction during her hospital stay.
• The patient tolerated ticagrelor well at 2 and 4 weeks following discharge, with no reported adverse events.

Conclusions:

• Ticagrelor, a P2Y12 inhibitor with a different chemical structure (cyclopentyltriazolopyrimidine) than thienopyridines, presents a lower theoretical risk of cross-reactivity.
• This case report demonstrates the safe and well-tolerated use of ticagrelor in a patient with a documented clopidogrel hypersensitivity.
• Ticagrelor may be a suitable alternative antiplatelet agent for patients with documented thienopyridine allergies, although further investigation is warranted.