Effects of Loratadine, Cetirizine, and Terfenadine on Histamine-Induced Wheal and Erythema Responses in Normal Canine Skin

This crossover study was performed in order to compare the effects of cetirizine, loratadine, and terfenadine in canine skin. Five healthy dogs were used. Cetirizine 0.5 mg/kg, loratadine 5 mg/kg and terfenadine 5 mg/kg were administered orally 4 hours before the experiment. Erythema indices and wheal size were assessed by Hexameter ($MX^{\circledR}$ 18, CK, Germany) and skin reaction guide, respectively. Cetirizine-induced erythema inhibition was generally higher than other drugs and was significantly different from placebo. Cetirizine was superior to placebo at 3, 4, 5, 6, 7, and 8 minutes (p< 0.01). Cetirizine also was superior to placebo at 9 minutes (p< 0.05). Loratadine and terfenadine erythema inhibition were better than after placebo treatment from 4 to 9 minutes, but erythema index of terfenadine at 7 minutes was not observed probability of 95% and 99%. At 10 minutes, intradermal injection of the histamine caused a mean wheal dimension for placebo, cetirizine, loratadine and terfenadine, which were 13.25$\pm$0.75 mm,7.5$\pm$ 1.02 mm (53% reduction, p<0.007),6.2$\pm$0.58 mm(43% reduction, p <0.01), and 8.4 $\pm$0.67 mm(37% reduction, p< 0.05), respectively, comparing with placebo. Loratadine and cetirizine were good antihistamines for clinical therapy for atopic dermatitis in dog.

개 피부에서 Histamine에 의한 팽진과 발적에 대한 loratadine, cetirizine과 terfenadine의 억제효과

아토피성 피부염은 면역계재성 피부질환으로 소양증이 주요 증상이며 이의 치료가 필수적이다. 따라서 개에서 제2세대 항히스타민제의 임상적용을 위해 피부에 히스타민에 의해 유발된 팽진과 발적에 대한 loratadine, cetirizine과 terfenadine의억제 효과를 비교하였다. 3종의 항히스타민제는 대조군에 비해 매우 유의하게 발적반응을 억제하였으며(p<0.01) cetirizine이 다른 제제에 비해 높은 억제효과를 보였다. 3종의 항히스타민제는 팽진 반응을 억제하는 효과를 보였으며 loratadine의 억제효과가 일정하며 지속적이었다. 따라서 제 2세대 항히스타민제인 loratadine과 cetirizine은 개에서 아토피성 피부염의 소양증 치료에 적용할 수 있는 항히스타민제로 사료된다. 특히 스테로이드제제를 대체할 수 있는 치료효과를 보일 것으로 판단된다.