Safety of celecoxib in patients with adverse skin reactions to acetaminophen (paracetamol) and nimesulide associated or not with common non-steroidal anti-inflammatory drugs.

Background: Acetaminophen (paracetamol--P) and Nimesulide (N) are widely used analgesic-antipyretic/anti-inflammatory drugs. The rate of adverse hypersensitivity reactions to these agents is generally low. On the contrary non-steroidal anti-inflammatory drugs (NSAIDs) are commonly involved in such reactions. Celecoxib (CE) is a novel drug, with high selectivity and affinity for COX-2 enzyme.
Objective: We evaluated the tolerability of CE in a group of patients with documented history of adverse cutaneous reactions to P and N associated or not to classic NSAIDs.
Methods: We studied 9 patients with hypersensitivity to P and N with or without associated reactions to classic NSAIDs. The diagnosis of P and N-induced skin reactions was based in vivo challenge. The placebo was blindly administered at the beginning of each challenge. After three days, a cumulative dosage of 200 mg of CE in refracted doses were given. After 2-3 days, a single dose of 200 mg was administered. All patients were observed for 6 hours after each challenge, and controlled again after 24 hours to exclude delayed reactions. The challenge was considered positive if one or more of the following appeared: erythema, rush or urticaria-angioedema.
Results: No reaction was observed with placebo and eight patients (88.8%) tolerated CE. Only one patient developed a moderate angioedema of the lips.
Conclusion: Only one hypersensitivity reaction to CE was documented among 9 P and N-highly NSAIDs intolerant patients. Thus, we conclude that CE is a reasonably safe alternative to be used in subjects who do not tolerate P and N.