The US Food and Drug Administration (FDA) communicated the potential cardiovascular risk of thiazolidinediones (rosiglitazone and pioglitazone) in 2007 and required a Risk Evaluation and Mitigation Strategy (REMS) for rosiglitazone in 2010. It also communicated in 2010 the potential risk of bladder cancer with pioglitazone use. This study examined the effects of these multiple FDA actions on utilization and reimbursed costs of thiazolidinediones in state Medicaid programs.
State Drug Utilization Data from the Centers for Medicare & Medicaid Services were assessed. An interrupted time series design and segmented linear regression models were used to examine changes in market shares according to both prescription volume and reimbursed costs for rosiglitazone and pioglitazone in the Northeast and Midwest regions of the United States after multiple FDA actions.
Compared with expected rates, there were relative reductions of 65.84% (Northeast region) and 55.09% (Midwest region) in the use of rosiglitazone at 1 year after the 2007 FDA actions for thiazolidinediones and cardiac risk. At the same time, relative increases of 7.30% and 9.28% in the use of pioglitazone were observed in the Northeast and Midwest regions, respectively. Changes in both use and costs of rosiglitazone after the 2010 REMS program could not be estimated because of the already low rates (~1%) before REMS was implemented. One year after the 2010 FDA actions for pioglitazone and its possible association with bladder cancer, relative reductions in pioglitazone use of 21.41% (Northeast region) and 18.12% (Midwest region) were detected.
The Northeast and Midwest regions reported similar patterns of changes after the FDA actions. Use and costs of rosiglitazone were substantially reduced after the 2007 FDA actions for cardiovascular risk, and this drug was rarely used after the 2010 REMS program. Conversely, use and costs of pioglitazone were substantially reduced after the 2010 FDA actions regarding the drug's possible risk of bladder cancer.