Availability and utilization of cardiovascular fixed-dose combination drugs in the United States.

Background: Solid clinical evidence supports the effectiveness and safety of multiple drugs in treating diabetes, dyslipidemia, and hypertension, and numerous fixed-dose combination products (FDCs) containing such drugs have been developed for patients with more severe forms of these diseases. We sought to evaluate the extent to which utilization of treatment combinations for these conditions corresponded to the availability of FDCs.

Methods: Using claims data from a large national commercial insurer, we identified 2 cohorts of patients: those who filled multiple single-agent drugs to treat diabetes, dyslipidemia, and hypertension in 2012, and those who used FDCs containing these products during the same period. We determined the fill rate of single-agent pairs and FDCs, availability of FDCs for the most frequently filled single-agent and drug class pairs, and the number of conditions treated by frequently filled single-agent pairs and FDCs.

Results: During our study period, 848,082 patients filled prescriptions for 3,248 unique single-agent pairs (mean 4.7 per patient, standard deviation [SD] 5.0); and 568,923 patients received prescriptions for 43 unique FDCs (mean 1.1 per patient, SD 0.3). Three (15%) of the 20 most frequently filled single-agent pairs were available as FDCs, whereas 9 (45%) of the 20 most frequently filled drug class pairs were available as FDCs. Nearly all of the frequently filled FDCs had lower fill rates than the most frequently filled single-agent pairs.

Conclusions: Utilization of drug combinations to treat cardiovascular conditions does not correspond well with availability of FDCs containing these agents. A concerted set of strategies should be implemented to streamline the development of useful combination products, including expedited approval pathways and increased investment in formulation studies.