Background: Despite the cost of pharmaceuticals, studies assessing prices of osteoporosis drugs are lacking. This study examined trends in prices of osteoporosis drugs in the United States in the period 1988–2014, assessed pricing structure of osteoporosis drugs, and evaluated price trends before and after generic drugs market entry.

Methods: Data were derived from the U.S. Food and Drug Administration, the RedBook, the Centers for Medicare & Medicaid Services, and the Federal Supply Schedule (FSS). Descriptive statistics and segmented linear regression analyses were performed.

Results: In the period 1988–2014, osteoporosis drug prices increased faster than the inflation. The average wholesale price (AWP) of generic products at market entry represented 90 percent of the AWP for the corresponding brand. Prices of brand products continued to increase after generic entry. Drug prices showed a significant variation when compared with the brand AWP. The brand wholesale acquisition cost (WAC) was typically set at 83.3 percent of the AWP. Community pharmacies acquired osteoporosis brand drugs at a median of 80.5 percent of the brand AWP. Significant reductions in brand AWP were observed for Medicare Part B (78.5 percent of the brand AWP), generic National Average Drug Acquisition Cost (33.7 percent), and FSS (22.5 percent).

Conclusions: There are significant differences in the manufacturer prices, pharmacy acquisition costs and reimbursement rates of osteoporosis drugs. Pharmaceutical companies listed prices are higher than the pharmacy actual estimated acquisitions costs, and the prices used for reimbursement to providers. Generic drugs entry significantly drives down prices; still, prices of branded drugs facing generic competition continued to increase after generic market entry.