Association between FDA black box warnings and Medicare formulary coverage changes.

Objective: To assess whether Medicare formularies restrict access to drugs receiving new FDA black box warnings for which safer drug alternatives are available.

Methods: A retrospective analysis using Medicare Prescription Drug Plan Formulary files to determine formulary changes for drugs receiving FDA black box warnings between 2007 and 2013. Methods: We identified all FDA-approved medications available in tablet or capsule formulation that received a black box warning between 2007 and 2013 related to death and/or cardiovascular risk. We then determined formulary coverage of these drugs pre-black box warning, 1 year after, and 2 years after. For each formulary, we identified formulary restrictiveness, defined as: unrestrictive coverage (no prior authorization or step therapy), restrictive coverage (prior authorization or step therapy required), or no coverage.

Results: Nine drugs with at least 1 FDA-approved safer drug alternative received 10 new black box warnings for death and/or cardiovascular risk between 2007 and 2013. In response to FDA black box warnings, overall formulary restrictiveness increased for 40% (n = 4) of drugs at 1 year, and for 50% (n = 5) at 2 years. However, for the majority of drugs (n = 7), most formularies remained unrestrictive 2 years after a new black box warning.

Conclusions: Medicare formularies became more restrictive for half of the drugs that recently received new FDA black box warnings for death and/or cardiovascular risk and for which safer drug alternatives are available. However, a substantial proportion of formularies remained unrestrictive, suggesting inconsistent responses to new safety information to curtail the use of these medications.