Immunologic tolerability profile of celecoxib.

Celecoxib is primarily an inhibitor of cyclooxygenase (COX) 2 and, at therapeutic concentrations in humans, does not inhibit the COX-1 isoenzyme. The present meta-analyses explore the incidence of allergic reactions with celecoxib in patients in the North American and international arthritis trials, in patients with a history of hypersensitivity reactions to sulfonamides, and in patients receiving medications containing sulfonamides. Data were obtained from 11,008 patients in 14 double-masked trials of celecoxib in arthritis ranging from 4 to 24 weeks in duration. Results demonstrate that the incidence of allergic reactions with celecoxib was not statistically different from that seen with placebo or active comparators (nonsteroidal anti-inflammatory drugs [NSAIDs]) when data from the entire cohort were analyzed. The subset of patients with a history of sulfonamide hypersensitivity reactions had a 3-fold to 6-fold higher incidence of dermatologic reactions than did the entire arthritis trial cohort. Although dermatologic reactions occurred with greater frequency in patients with a history of sulfonamide hypersensitivity, the trend was consistent across all 3 treatment groups (celecoxib, NSAIDs, and placebo). According to these data and structural and metabolic differences between sulfonamides, the potential for cross-allergenicity between celecoxib and other sulfonamide-containing medications appears comparable to that of placebo and nonsulfonamide-containing NSAIDs. Additionally, the risk of allergic reactions with celecoxib appears comparable to that of placebo and comparator NSAIDs. Prospective trials are needed to confirm these findings.