COX-2-specific inhibitors: prescribing patterns in a large managed care health system and strategies to minimize costs.

OBJECTIVE: To determine the relative costs associated with the exclusive use of celecoxib versus rofecoxib in a large managed care system. STUDY DESIGN: A retrospective review of all calendar year 2000 prescriptions dispensed for celecoxib and rofecoxib in the Veterans Affairs (VA) system. METHODS: The primary data points included drug strength, quantity dispensed, and days supply for the prescription. The cost minimization model described in Federal Practitioner (1999;16[4]:41-44) was used to calculate the cost savings. The mean once-daily dosing rates and their 95% confidence intervals were determined by binomial data analysis. Calendar year 2001 utilization and cost projections were derived by linear regression trend analysis. RESULTS: Current VA system costs per dose are celecoxib 100 mg $0.66; celecoxib 200 mg $1.32; rofecoxib (12.5 or 25 mg) $1.32; rofecoxib 50 mg $2.14. During calendar year 2000, the VA spent $13.8 million and $4.2 million on celecoxib and rofecoxib, respectively. The percentage of once-daily or less than once-daily dosing was celecoxib 100 mg (17%), celecoxib 200 mg (67%), celecoxib overall (49%), rofecoxib 12.5 mg (86%), rofecoxib 25 mg (94%), rofecoxib 50 mg (100%), and rofecoxib overall (93%). Based on current utilization, if all celecoxib prescriptions were changed to rofecoxib, the VA would have realized annual cost savings of $2.1 million in calendar year 2000. In calendar year 2001, projected cost savings could total $5.2 million. This potential savings is largely due to the high prevalence of twice-daily celecoxib dosing. CONCLUSION: The results of the cyclooxygenase-2 cost minimization analysis provide a compelling argument for the preferred use of rofecoxib in the VA system, and potentially in other managed care systems.