Rhabdomyolysis precipitated by possible interaction of ticagrelor with high-dose atorvastatin.

Objective: To report a case of rhabdomyolysis possibly caused by interaction of ticagrelor with high-dose atorvastatin. Summary: A 62-year-old woman originally from India underwent uncomplicated percutaneous coronary intervention following ST-elevation myocardial infarction. The patient was discharged on a secondary prevention drug regimen that included ticagrelor 90 mg twice daily, atorvastatin 80 mg once daily, metoprolol 25 mg twice daily, and aspirin 81 mg daily. Two months later, the patient was readmitted with complaints of muscle pain, nausea, vomiting, and poor oral intake. The patient was diagnosed with rhabdomyolysis based on her symptoms combined with elevated creatine kinase, urine myoglobin, and serum creatinine. Intravenous fluids were initiated and atorvastatin held. Throughout the second hospital stay, serial laboratory values revealed a decrease in creatine kinase and resolution of acute kidney injury and muscle pain. The patient was discharged on aspirin and clopidogrel. Low-dose statin therapy was started at a follow-up appointment with close monitoring without recurrence of rhabdomyolysis. Results: A drug interaction between the cytochrome P450 3A4 inhibitor ticagrelor and substrate atorvastatin 80 mg may have precipitated development of rhabdomyolysis in this patient. The probability of this drug interaction is rated as "possible" on both the Naranjo Adverse Drug Reaction Probability Scale and the Drug Interaction Probability Scale. Conclusion: Rhabdomyolysis was observed possibly because of a drug interaction between once-daily ticagrelor and atorvastatin 80 mg. Clinicians need to be aware of this possible drug interaction via CYP3A4 and potential complications. [ABSTRACT FROM AUTHOR]