Nationwide Trends in Dispensing of Sodium Glucose Cotransporter 2 Inhibitors

Abstract

Background: Three large cardiovascular outcome trials have investigated the safety of sodium glucose cotransporter 2 (SGLT2) inhibitors. Objective: To analyze the nationwide dispensing of SGLT2 inhibitors before and after the publication of these trials. Methods: A cross-sectional study was conducted of monthly prescription dispensing of SGLT2 inhibitors from May 23, 2014, to April 30, 2019, using nationwide data for Canada. An autoregressive integrated moving average (ARIMA) model was fitted to the monthly number of tablets dispensed for each SGLT2 inhibitor; the model included a ramp intervention function at the publication dates of interest to estimate the impact on SGLT2 inhibitor dispensing patterns. Results: The rate of canagliflozin and dapagliflozin dispensing declined after publication of results of the empagliflozin cardiovascular trial in September 2015. After publication of results of the canagliflozin trial in June 2017, which indicated a reduction in cardiovascular events and an increase in the risk of lower-limb amputation, canagliflozin remained the most commonly dispensed SGLT2 inhibitor, but its rate of dispensing declined further. In contrast, the rate of empagliflozin dispensing increased, while the rate of dapagliflozin dispensing was unchanged. After publication of the dapagliflozin trial in November 2018, which indicated no clear reduction in cardiovascular events, short-term trends in dispensing of canagliflozin, empagliflozin, and dapagliflozin were largely unaffected. Conclusions: The cardiovascular outcome trials appeared to have an important impact on the dispensing of SGLT2 inhibitors in Canada.