商品名：Chlortrimeton and Phenetron
Antihistamine (H1-blocker). Similar to other antihistamines, it acts by blocking the H1 receptor and suppresses inflammatory reactions caused by histamine. The H1-blockers have been used to control pruritus and skin inflammation in dogs and cats. Other commonly used antihistamines include clemastine, chlorpheniramine, diphenhydramine, cetirizine, and hydroxyzine.
Chlorpheniramine is used to prevent allergic reactions and for pruritus therapy in dogs and cats. However, success rates for treatment of pruritus have not been high. In addition to the antihistamine effect for treating allergies, these drugs block the effect of histamine in the vomiting center, vestibular center, and other centers that control vomiting in animals. Use in animals has been primarily derived from empirical use. There is a lack of well-controlled clinical studies or efficacy trials to document clinical effectiveness.
劑量數字暫停提供：VetPro 的劑量改依 DRUGAPI 藥物資料庫對外的內容，DRUGAPI 目前不提供可直接計算的劑量。下方列出 DRUGAPI 的審查結論與劑量審查引用的來源；計算機可手動輸入劑量換算。
D0149／D0150 尚未 canonical 合併；口服指引、澳洲具名 SC／IM 產品、游離鹼／maleate 濃度與不同頻率不可合併計算。
DRUGAPI 劑量審查引用的獸醫官方標示（各標示只適用於其產品、物種與法域，不可互換）
依出現頻率分組；嚴重副作用獨立列出，臨床上需立即辨識。
renal