RESUMEN
Chronic idiopathic urticaria is a major problem in every day practice. H1 antagonist anti-histamines are the drugs of choice for its symptomatic treatment. The ordinary sedating anti-histamines are replaced by the non-sedating group. Terfenadine Astemizole and Loratadine are members of this group. The three drugs were assessed in an open label study for 4 weeks in treating 80 patients with chronic urticaria who completed the study. It came to the conclusion that the 3 drugs have significant effects in controlling the pruritus in different degrees. Loratadine was proved to be superior than Astemizole in efficacy but the difference was not statistically significant, P = 0.46. Both Loratadine and Astemizole were superior than Terfenadine in efficacy with a significant statistical difference, P < 09.05 for Astemizole/Terfenadine. No side reactions were reported in patients taking Loratadine and Astemizole, but only one patient [4%] in the Terfenadine group had dry mouth and one patient [4%] had eye irritation