Influence of health warnings on the use of rosiglitazone and pioglitazone in an area of Spain: A time-series study

BACKGROUND Throughout 2007 and January 2008, several glitazones health warnings were published on rosiglitazone myocardial infarction risk. The impact of such warnings on glitazones prevalence of utilization has been extensively studied in the United States but only in one European country (England), which has showed different pattern from US studies. The aim of this study is to evaluate the impact of such safety warnings on glitazones utilization in an area of another European country. METHODS We calculated the number of defined daily doses per thousand inhabitants per day of glitazones each month during the period from 2006 to 2008 in a health area of Spain. We analyzed the data graphically and through a segmented regression analysis. RESULTS Rosiglitazone defined daily doses per thousand inhabitants per day were growing before the safety warnings, after the warnings a change in trend occurred and rosiglitazone utilization showed a downturn slope. Pioglitazone defined daily doses per thousand inhabitants per day were stable before the safety warnings, and a linear growth was observed after the safety warnings. Throughout the study period, rosiglitazone defined daily doses per thousand inhabitants per day were higher than pioglitazone defined daily doses per thousand inhabitants per day until near the end of 2008. CONCLUSION Despite the fact that cardiovascular warnings affected rosiglitazone and not pioglitazone, rosiglitazone was more utilized than pioglitazone until near the end of 2008 which is a pattern similar to the one found in another European studies in England, but very different from studies in the United States, where rosiglitazone was less utilized than pioglitazone from the first month after rosiglitazone cardiovascular safety warnings.