Ebastine - An update of its use in allergic disorders

Ebastine is a second-generation antihistamine which undergoes transformatio n to its active metabolite, carebastine. Its antihistaminic and antiallergi c effects have been demonstrated in in vitro and in vivo studies, in additi on to data obtained from clinical trials. Patients with allergic rhinitis or chronic idiopathic urticaria experienced significant improvement in their symptoms with ebastine 10 or 20mg once da ily. Some studies in patients with seasonal allergic rhinitis (SAR) have in dicated trends towards greater efficacy with the 20mg than the 10mg dose, a lthough only 1 study has shown statistically significant benefits. In compa rative trials in patients with SAR, ebastine 10mg was as effective as most other second-generation antihistamines, including astemizole, azelastine, c etirizine, loratadine and terfenadine. Ebastine 20 mg/day was significantly superior to loratadine 10 mg/day in patients with SAR according to effects on secondary efficacy variables in comparative studies; 1 study found sign ificantly greater changes from baseline in mean total symptom score with eb astine 20mg (-43 vs -36% with loratadine, p = 0.035). In patients with pere nnial allergic rhinitis, ebastine 10 or 20mg daily was significantly more e ffective than loratadine in reducing total symptom scores from baseline in 1 comparative study. There have been no reports of serious adverse cardiac effects during ebasti ne therapy. Increases in corrected QT interval have been observed during cl inical trials; however, these have not been considered clinically significa nt and were generally of similar magnitude to those seen with loratadine. T he normal diurnal variation in QTc interval and the problems associated in correcting for changes in heart rate also complicate assessment of this iss ue. The incidence of adverse events during ebastine treatment is not signif icantly greater than that observed with placebo or other second-generation antihistamines. Conclusions: Ebastine 10mg daily is a well tolerated and effective treatmen t for allergic rhinitis and chronic idiopathic urticaria. At this dosage, i t is as effective as the other second-generation antihistamines against whi ch it has been compared. Ebastine 20mg has similar tolerability to the 10mg dose, and trends towards greater efficacy with the higher dose have been s hown in some studies. Ebastine does not appear to be associated with any si gnificant cardiac adverse events. Ebastine is a useful treatment option fur patients with allergic rhinitis or chronic idiopathic urticaria.