商品名：Benadryl
Antihistamine (H1 blocker). Diphenhydramine is the active moiety of dimenhydrinate (Dramamine). Similar to other antihistamines, it acts by blocking the H1 receptor (H1) and suppresses inflammatory reactions caused by histamine. Commonly used antihistamines include clemastine, chlorpheniramine, diphenhydramine, and hydroxyzine.
Diphenhydramine, like other antihistamines, 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.
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。
確認動物種類、診斷與治療目標；不同物種不可互相外推。 確認確切成分與含量採游離有效成分或鹽基準。 確認產品、單方或複方、賦形劑、法域、許可證、效期、可得性與現行標示。 審查青光眼、癲癇、心血管、呼吸、甲狀腺、攝護腺、腸胃或泌尿阻塞、肝腎功能、懷孕哺乳與所有同時用藥。 嚴重過敏須依急診流程處置；本藥不能取代腎上腺素與支持治療。 未完成個案、產品、途徑、用途與監測合約前，不產生計算或處方結果。
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。