Increasing use of amiodarone in Norway

Abstract

Abstract Background Amiodarone may be used against ventricular arrhythmias to reduce ICD-shocks, and for rhythm control in patients with atrial fibrillation. The 2020 ESC atrial fibrillation guidelines upgraded the recommendation for amiodarone in rhythm control to class I, level of evidence A, although still with a caution to consider other antiarrhythmic drugs first. Amiodarone is the most potent antiarrhythmic drug in clinical use, but it has frequent and potentially severe side effects affecting several organ systems. We have seen an increasing number of patients with amiodarone-induced thyrotoxicosis. Purpose We wanted to study the prescription rate of amiodarone in Norway, which indications were most prevalent, and whether there had been any changes over time. Methods From the Norwegian Prescription Registry, we have collected data on how many patients had received amiodarone, and the number of defined daily doses delivered (DDDs), related to various reimbursement categories. Results From 2010 to 2019, the number of individuals receiving amiodarone from a pharmacy in Norway increased from 5359 to 7789 (45% increase), and the number of DDDs delivered from 994905 to 1412796 (42% increase) (Figure). With an atrial fibrillation-related reimbursement code, we found during the same period an increase of individuals from 3616 to 5776 (60% increase) and number of DDDs from 661531 to 1061601 (60% increase). The dispenses for ventricular arrhythmia-related reimbursement codes were close to unchanged during the same period of years (Figure). The fraction of amiodarone use related to atrial fibrillation increased from 66% in 2009 to 75% in 2019. Conclusion We observed a 42–45% increase in the total use of amiodarone over 10 years, and almost the whole increase was related to atrial fibrillation. In 2019, atrial fibrillation-related diagnoses accounted for 75% of the total amount of amiodarone dispensed in Norway. Due to the several side effects of amiodarone, we are concerned if the threshold for use of amiodarone diminishes. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Norwegian Institute of Public HealthOslo University Hospital, Rikshospitalet Number of patientsNumber of DDDs