Ticagrelor and Primidone Interaction Masquerading as Dual Antiplatelet Therapy Noncompliance

Abstract

Ticagrelor and aspirin is a common dual antiplatelet therapy regimen for patients who undergo percutaneous coronary intervention. Despite its ability to significantly reduce cardiovascular complications, ticagrelor response may be altered by other medications causing subtherapeutic effects. Traditionally, ticagrelor is thought to have fewer drug–drug interactions compared to other thienopyridine antiplatelet medications such as clopidogrel. Primidone, metabolized into phenobarbital, is a strong CYP-3A inducer that can reduce serum concentrations of ticagrelor resulting in ineffective antiplatelet therapy. We present a 67-year-old male who suffered in-stent thrombosis after percutaneous intervention possibly due to the interaction between primidone and ticagrelor.

Plain Language Summary

Ticagrelor and aspirin is a common antiplatelet regimen for patients who undergo coronary intervention and stent implantation. Ticagrelor is typically less associated with drug–drug interactions; however, our case illustrates an interaction between ticagrelor and primidone causing acute in-stent thrombosis to recently implanted drug-eluting stents.

Keywords: :

• acute coronary syndrome
• clopidogrel
• coronary artery disease
• percutaneous coronary intervention
• primidone
• ticagrelor

Author contributions

H Patail: Primary authorship, conceptualization, literature review, writing, editing, data gathering and imaging gathering. A Ghani: Secondary procedural operator (second PCI), literature review, writing, editing, data gathering and imaging gathering and interpretation. C Nagle: Primary clinical investigation of drug interaction, literature review, writing, editing, data interpretation and imaging interpretation. R McKay: Literature review, writing, editing, data interpretation and imaging interpretation. A Rizvi: Primary procedural operator (first PCI), writing, editing, data interpretation and imaging interpretation. J Haider: Primary procedural operator (second PCI), conceptualization, attending of record, writing, editing, data interpretation and imaging gathering and interpretation. This case has been submitted and accepted as an abstract to ACC Complex Clinical Cases. Patient permission obtained for the educational use of the case, presentation and outcomes.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Informed consent disclosure

Verbal consent was obtained for the academic use of this case, and we confirm there are no patient identifiable factors within this manuscript.