Tolerability of nimesulide and paracetamol in patients with NSAID-induced urticaria/angioedema

Previous studies evaluated the tolerance of nimesulide and paracetamol in s ubjects with cutaneous, respiratory and anaphylactoid reactions induced by nonsteroidal anti-inflammatory drugs (NSAIDs). In this study we investigated tolerability and reliability of nimesulide an d paracetamol in a very large number of patients with an exclusive well-doc umented history of NSAID-induced urticaria/angioedema. Furthermore, we eval uated whether some factors have the potential to increase the risk of react ion to paracetamol and nimesulide. A single-placebo-controlled oral challenge procedure with nimesulide or par acetamol was applied to 829 patients with a history of NSAID-induced urtica ria/angioedema. A total of 75/829 (9.4%) patients experienced reactions to nimesulide or pa racetamol. Of the 715 patients tested with nimesulide 62 (8.6%) showed a po sitive test. while of 114 subjects submitted to the challenge with paraceta mol. 13 (9.6%) did not tolerate this drug. Furthermore, 18.28% of patients with a history of chronic urticaria and 11.8% of subjects with an history o f NSAID-induced urticaria/angioedema or angioedema alone (with or without c hronic urticaria) resulted to be intolerant to alternative drugs. Taken together, our results confirm the good tolerability of nimesulide and paracetamol in patients who experienced urticaria/angioedema caused by NSA IDs. However, the risk of reaction to these alternative study drugs is stat istically increased by a history of chronic urticaria and, above all, by a history of NSAID-induced angioedema.