Antiarrhythmic drugs are widely used in the treatment of supraventricular and ventricular arrhythmias. Yet, nationwide long-term utilization trends remain unexplored. We examined 19-year trends in the use of antiarrhythmic drugs in Denmark. Using nationwide prescription data, we obtained information on hospital and primary healthcare use of Class I-V antiarrhythmic drugs from 1999 to 2017. Data was stratified according to sex and age groups. From 1999 to 2017, the total use of antiarrhythmic drugs per 1000 inhabitants/day increased 16% from 36.3 in 1999 to 41.9 in 2017 with peak consumption in 2008 (46.5). In primary healthcare, Class I usage decreased from 0.8 to 0.5 defined daily doses (DDD) per 1000 inhabitants/day, driven by a decreased prescription rate of propafenone (0.4 to 0.1) whereas prescription of flecainide (Class Ic) increased from 0.3 to 0.4 DDD per 1000 inhabitants/day (mainly in men of age 45 to 79 years). Class II usage increased from 15.4 to 33.6 DDD per 1000 inhabitants/day. Class III usage decreased from 2.6 to 1.1 DDD per 1000 inhabitants/day, reflecting reduced prescription rate of sotalol (2.1 to 0.2) whereas amiodarone increased from 0.5 to 0.9 (mainly due to increased prescription among men and women >80 years). Class IV usage declined from 8.6 to 2.8 DDD per 1000 inhabitants/day. Finally, Class V drugs decreased 8.1 to 3.3 DDD per 1000 inhabitants/day. In conclusion, during the past 2 decades considerable changes in prescription rate of antiarrhythmic drugs have occurred, most notably a reduction in sotalol and increased usage of flecainide, Class II drugs, and amiodarone.