Impact of regulatory interventions to restrict the combined use of renin–angiotensin system blockers: A Danish nationwide drug utilisation study

This study aimed to evaluate the impact of the risk minimisation measures issued by the European Medicines Agency in 2014 to restrict the combined use of renin–angiotensin system (RAS) blocking agents in Denmark. Data from the Danish National Prescription Registry covering all medications dispensed during January 2008–December 2018 was used. The outcome was monthly prevalence of patients codispensed RAS blockers. Autoregressive integrated moving average interrupted time series regression was used to evaluate dispensing trends. The prevalence of patients codispensed RAS blockers decreased from 0.01 to 0.0003%. Preintervention trend was declining and further decreased with an additional −0.45 (95% confidence interval −0.66, −0.25) codispensing per million population after the intervention. Overall, the intervention had minimal impact on the combined use of RAS blockers. However, as the combined use of RAS blockers is low, further interventions to restrict the combined use of RAS blockers may not be required in Denmark at this point.