Cetirizine premedication prevents acute urticaria induced by weak COX-1 inhibitors in multiple NSAID reactors.

BACKGROUND In multiple NSAID reactors, intolerance to weak COX-1 inhibitors may pose relevant therapeutic problems when painful, febrile or rheumatic disorders co-exist. OBJECTIVE To assess whether pre-medication with a second generation antihistamine is able to prevent urticaria induced by "alternative" NSAIDs. METHODS 87 with a history of urticaria following the administration of multiple, chemically unrelated NSAID underwent 250 oral tolerance tests with alternative drugs exerting little or no COX-1 inhibition (paracetamol, coxibs, nimesulide, tramadol). Twenty-eight challenges scored positive in 21 subjects: 8, 5, 9, and 6 reactions were induced by paracetamol, tramadol, coxibs, and nimesulide, respectively. Thirteen of 21 underwent a new oral challenge with the offending drug(s) 2-6 hours after taking cetitrizine 10 mg. RESULTS All the drugs were tolerated on re-challenge except paracetamol that was not tolerated in 2/4 cases. CONCLUSION In most cases urticaria induced by alternative drugs exerting little or no COX 1-inhibition is slight, and can be adequately prevented by oral antihistamine pre-medication. These observations open new opportunities for patients with multiple NSAIDs intolerance that have to treat painful or febrile conditions or rheumatic disorders.