Allergic reaction to prasugrel and cross-reactivity with clopidogrel

Ticagrelor-Induced Angioedema: A Rare and Unexpected Phenomenon

Angioedema can cause potentially life-threatening airway obstruction. This case report describes an exceedingly rare episode of ticagrelor-induced hypersensitivity reaction, manifesting as angioedema with periorbital and likely respiratory involvement. The heart team should be vigilant for this precarious condition which may require emergent airway management. Desensitization protocols and alternative regimens (e.g., clopidogrel, prasugrel, and addition of an adjunctive anticoagulant) should be considered when there is an absolute indication for antiplatelet therapy.

Prasugrel hydrochloride for the treatment of acute coronary syndrome patients

INTRODUCTION

Dual antiplatelet therapy (DAPT) with aspirin combined with either a thienopyridine (clopidogrel or prasugrel) or acyclopentyl-triazolo-pyrimidine (ticagrelor) plays a vital role in the management of acute coronary syndrome (ACS) especially in those undergoing percutaneous coronary intervention (PCI) but even those being managed medically. Observational studies and some formal studies have shown patients on the standard dual antiplatelet regimen (clopidogrel and aspirin) continue to have further ischemic events and can suffer stent thrombosis. It has been demonstrated that clopidogrel is associated with a delayed onset of action with a considerable inter-individual variation to treatment thus making it difficult to achieve an optimal level of platelet inhibition. Areas covered: This article will review the current evidence that is available regarding the effectiveness and safety of prasugrel in ACS patients undergoing percutaneous coronary intervention (PCI). Expert commentary: Prasugrel is an oral third-generation inhibitor of platelet activation and aggregation. Laboratory studies and early phase clinical trials show prasugrel has a faster onset of action, is more potent and has reduced inter-patient response variability compared to clopidogrel. The published studies so far demonstrated that prasugrel when compared to clopidogrel also shows a higher degree of effectiveness in the prevention of platelet-initiated thrombotic events in patients with ACS undergoing PCI, however these benefits are offset somewhat by an increased bleeding risk.

A joint allergist/cardiologist classification for thienopyridines hypersensitivity reactions based on their symptomatic patterns and its impact on the management strategies

The role and importance of thienopyridines such as ticlopidine, clopidogrel, and prasugrel is well-established for several indications, ranging from prevention of acute coronary syndromes to percutaneous coronary interventions, where the dual antiplatelet therapy represents the gold standard to avoid denovo coronary stenosis. However, there is a significant cohort of patients with coronary artery disease who may manifest hypersensitivity reactions to thienopyridines. The examination of the various case reports from medical literature leads to identify mainly four clinical patterns of hypersensitivity to thienopyridines which involves more frequently cutaneous, hematologic, and articular tissues, therefore the kind and predominance of clinical symptoms may determine a different clinical approach to overcome or neutralize thienopyridines hypersensitivity.

Prasugrel hypersensitivity with respiratory distress and rash

Purpose

An adverse drug reaction associated with the use of prasugrel for dual antiplatelet therapy after percutaneous coronary intervention (PCI) with stent placement is reported.

Summary

About one week after starting prasugrel use following angioplasty and a stent revision procedure, a 61-year-old woman arrived in the emergency department with wheezing, shortness of breath, a feeling of throat closure, and a widespread erythematous, maculopapular, pruritic rash. She reported that the respiratory symptoms had started to develop the previous day, with the onset of rash occurring about 24 hours after initiation of prasugrel therapy. The patient’s symptoms subsided after administration of 0.3 mg epinephrine subcutaneously, diphenhydramine 50 mg i.v., and methylprednisolone 125 mg i.v. Prasugrel was discontinued, and the patient was switched to another P2Y12 inhibitor (ticagrelor) for continued dual antiplatelet therapy. Analysis of the case using the adverse drug reaction probability scale of Naranjo et al. indicated that prasugrel was the probable cause of the hypersensitivity reaction. Hypersensitivity manifesting as a rash has been previously reported in patients receiving prasugrel, a thienopyridine P2Y12 inhibitor. Desensitization may be an option for thienopyridine-allergic patients undergoing PCI with stenting; alternatively, the nonthienopyridine P2Y12 inhibitor ticagrelor may be used in a dual antiplatelet therapy regimen.

Conclusion

A patient who had undergone PCI with stenting developed shortness of breath and rash associated with prasugrel therapy. Symptoms abated after supportive therapy and discontinuation of prasugrel, the probable offending agent. Treatment was safely switched to ticagrelor.

Ticagrelor Use in a Patient With a Documented Clopidogrel Hypersensitivity

Objective: To report the use of ticagrelor in a patient with a documented hypersensitivity reaction to clopidogrel. Case Summary: A 64-year-old woman presented with non-ST-segment elevation myocardial infarction (NSTEMI) with a history significant for a hypersensitivity reaction to clopidogrel and was medically managed. Based on the patient’s past medical history and current evidence available, the determination was made to use ticagrelor in this patient. Ticagrelor was administered without reaction during the hospital stay and on assessment at 2 and 4 weeks postdischarge. Discussion: Hypersensitivity occurs in approximately 1% of patients receiving clopidogrel. Although the risk of hypersensitivity reaction to clopidogrel is low, evidence to support alternative antiplatelets in this setting is relatively limited. Prasugrel has a similar structure to clopidogrel and, therefore, may cross-react. Furthermore, prasugrel is not recommended in the medical management of NSTEMI. Ticagrelor is a newer P2Y12 inhibitor that contains a cyclopentyltriazolopyrimidine structure. Because of the difference in structure, a lower theoretical risk of cross-reactivity with the thienopyridines would be anticipated. However, there are no reports to date that investigate the use of this agent in patients with a documented thienopyridine allergy. Conclusions: The current case report describes the use of ticagrelor in a patient with documented hypersensitivity to clopidogrel. In this patient, ticagrelor was well tolerated during hospital admission and at 2 and 4 weeks postdischarge following administration.