Drug switching patterns among patients with rheumatoid arthritis and osteoarthritis using COX-2 specific inhibitors and non-specific NSAIDs.
OBJECTIVE
To compare RA and OA patients' time-to-switch after newly initiating treatment with three most commonly used non-specific (NS)-NSAIDs and two COX-2 inhibitors, celecoxib and rofecoxib.


METHODS
Managed care enrollees newly prescribed celecoxib, rofecoxib, ibuprofen, naproxen or diclofenac were identified. Time to switch to a different NS-NSAID or COX-2 specific inhibitor was determined using time-to-event analysis and Cox proportional hazards models were used to estimate the odds ratio (OR) after controlling for potential confounders.


RESULTS
The time to 25% of the cohort switching was longer for rofecoxib and celecoxib (159 and 205 days respectively) compared to the three NS-NSAIDs (49-78 days). Patients were at the highest risk of switching within the first 100 days of therapy. After adjusting for potential confounding factors, the OR for switching to another NS-NSAID or COX-2 specific inhibitor ranged from 1.74 to 2.35 for the three NS-NSAIDs compared to celecoxib (all comparisons, p < 0.01). Similar findings were obtained when comparing rofecoxib to each of the three NS-NSAIDS (all comparisons, p < 0.01). When COX-2 inhibitors combined were compared to NS-NSAIDS combined, the OR for switching was 1.53 (95% confidence interval = 1.42-1.65; p < 0.01) after adjusting for potential confounders.


CONCLUSIONS
Patients on the COX-2 specific inhibitors (celecoxib and rofecoxib) were significantly less likely to switch their therapy than patients on NS-NSAIDS (ibuprofen, naproxen and diclofenac). These results suggest that COX-2 specific inhibitors may be a more effective treatment option when compared with NS-NSAIDs in usual clinical practice.
Zhao
Sean Z
SZ
Pharmacia Global Health Outcomes, Peapack, NJ, USA.
Wentworth
Chuck
C
Burke
Thomas A
TA
Makuch
Robert W
RW
D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000188:drug therapy*; D000068579:Celecoxib; D016861:Cyclooxygenase Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D005767:Gastrointestinal Diseases / Q000150:complications; D006801:Humans; D007783:Lactones / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000150:complications / Q000188:drug therapy*; D017891:Pharmacoepidemiology; D016016:Proportional Hazards Models; D011720:Pyrazoles; D013449:Sulfonamides / Q000008:administration & dosage / Q000627:therapeutic use*; D013450:Sulfones; D013997:Time Factors
D000894:Anti-Inflammatory Agents, Non-Steroidal; D016861:Cyclooxygenase Inhibitors; D007783:Lactones; D011720:Pyrazoles; D013449:Sulfonamides; D013450:Sulfones; C116926:rofecoxib; D000068579:Celecoxib