Rosiglitazone use and associated adverse event rates in Canada: an updated analysis

BACKGROUND: We previously reported on the change in the use of rosiglitazone-containing products (RCP) and adverse event reporting rates in Canadian patients between 2004 and 2010. The present study extends this analysis to include the January 2011 to December 2012 time period. METHODS: RCP utilization rates were obtained from IMS Health Brogan’s longitudinal de-identified patient database, LRx. GlaxoSmithKline’s global adverse events database was used to extract adverse events (AE), serious adverse events (SAE), and cardiac adverse events (CAE) reported in Canadian patients receiving RCP from April 2004 to December 2012. The patient utilization information from the LRx database was used to estimate rates per 100,000 patients. RESULTS: An estimated 182,841 patients were dispensed RCP prescriptions between April 2004 and December 2012. The total number of patients using RCP decreased by 85 % from 2011 to 2012. From its peak use in 2007, the number of patients filling a prescription decreased 97 %. A total of 1069 AEs were reported during the study period, of which 32 AE’s were reported from Jan 2011 to Dec 2012. The average monthly reporting rates of AE’s, SAE’s and CAE’s over 2011–2012 were 10.8/100,000 patients, 9.1/100,000 patients and 5.0/100,000 patients, respectively. CONCLUSIONS: The utilization of RCP in Canada has significantly declined. The significance of the adverse event rate information presented is uncertain and must be evaluated within the context of the well known factors that can influence AE reporting rates, as well as limitations to the methods used to estimate these reporting rates.