西替利嗪
Cetirizine
Cetirizine HCl
別名: Zyrtec · Piriteze · Zirtec · UCB-P071 · P-071 · cetirizina · cetirizini · ceterizino · Cetirizine hydrochloride · Cetirizinum
由 VetSheet 獸醫團隊審訂更新於 2026年4月5日本內容以實證獸醫文獻為本
劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。
各物種劑量
🌎 NA — North America🌍 EU — Europe
狗
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| For atopic dermatitis | 1 mg/kg PO once daily with or without food | PO | q24h | — | 🌎 NA |
| For atopic dermatitis | 5-10 mg (total dose) PO once daily | PO | q24h | — | 🌎 NA |
| For allergic dermatitis | 1 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
| For adjunctive treatment of pruritus | 0.5-1 mg/kg or 5-10 mg total dose once to twice daily | PO | q12-24h | — | 🌎 NA |
- For atopic dermatitis: Satisfactory control of pruritus in 18% of dogs evaluated in the study.
貓
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| For adjunctive treatment of non-responsive chronic rhinosinusitis | 5 mg (total dose) PO q12h | PO | q12h | — | 🌎 NA |
| General antihistamine use | 5 mg (total dose) per cat PO once daily | PO | q24h | — | 🌎 NA |
| For adjunctive treatment of pruritus | 2.5-5 mg (total dose) per cat once daily | PO | q24h | — | 🌎 NA |
- General antihistamine use: No controlled studies evaluating effectiveness against other antihistamines.
馬
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Antihistamine | 0.2-0.4 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
- Antihistamine: Based on pharmacokinetic and pharmacodynamic data, may be a useful antihistamine in horses.
劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。
概覽
西替利嗪 (Cetirizine) 是一種第二代抗組織胺藥，廣泛應用於人類醫學，並越來越多地應用於獸醫臨床，作為犬貓過敏及組織胺介導的搔癢症狀的輔助治療。
- 無嗜睡特性：與第一代抗組織胺（如苯海拉明）不同，西替利嗪在標準劑量下難以穿透血腦屏障，因此較不易引起嗜睡。
- 活性代謝物：它是哌嗪類衍生物，也是羥嗪 (Hydroxyzine) 的主要人類活性代謝物。
- 臨床應用：主要用於犬貓的異位性皮膚炎、貓慢性鼻竇炎的輔助治療，偶爾用於馬的過敏症狀。雖然抗組織胺單獨使用於寵物嚴重過敏發作的效果不如人類顯著，但作為多模式、減少類固醇用量療法的一部分，仍具有臨床價值。
作用機制
Cetirizine acts as a highly selective, competitive antagonist at peripheral H1 receptors.
- Allergic cascade: Allergen exposure → Mast cell/basophil degranulation → Histamine release → Binds to H1 receptors on sensory nerve endings and blood vessels → Pruritus, vasodilation, and edema.
- Cetirizine competitively blocks this binding, preventing histamine-mediated effects.
- It also appears to decrease histamine release from basophils in some species, though experimental studies in cats showed it does not reduce eosinophilic airway inflammation.
- It lacks significant anticholinergic or anti-serotonergic activity, and tolerance to its antihistaminic effects is not thought to occur.
安全性與警告
禁忌症
- Hypersensitivity to cetirizine or hydroxyzine
- Combination products containing pseudoephedrine (e.g., Zyrtec-D) are strictly contraindicated in dogs and cats
不良反應
- Vomiting
- Hypersalivation (drooling)
- Somnolence (drowsiness/sedation, especially in small dogs at higher dosages)
- Dry mouth (reported in humans)
注意事項
CRITICAL WARNING: Combination products containing pseudoephedrine (e.g., Zyrtec-D) are highly toxic to dogs and cats and must never be used.
- Organ Impairment: Dosage adjustment is recommended in patients with severe renal or hepatic impairment, as the drug is primarily excreted unchanged in the urine.
- Allergy Testing: Discontinue medication well in advance of any hypersensitivity (intradermal) skin testing to avoid false-negative results.
- Pregnancy/Nursing: Categorized as FDA Category B in humans. Approximately 3% of a dose is excreted into milk in Beagles; while probably safe, caution is advised in nursing animals.
藥物相互作用
Additive CNS depression if used concurrently with cetirizine
監測
- Clinical efficacy (reduction in pruritus or allergic signs)
- Adverse effects (vomiting, hypersalivation, somnolence)
藥物動力學
半衰期
吸收
In humans, peak concentrations occur in about 1 hour. Food can delay, but not affect the extent of, absorption.
分佈
In cats, volume of distribution is 0.26 L/kg. It is 93% bound to human plasma proteins. Brain levels are approximately 10% of those found in plasma, explaining its non-sedating nature.
代謝
It is a human metabolite of hydroxyzine.
排除
In cats, clearance is about 0.3 mL/L/minute. In humans, approximately 80% is excreted in the urine, primarily as unchanged drug.
過量
Cetirizine generally has a wide margin of safety.
- Massive Overdose: May cross the blood-brain barrier in overdose situations, leading to neurologic signs (hyperactivity or severe sedation).
- Cardiovascular Safety: Unlike earlier non-sedating antihistamines (terfenadine and astemizole), cetirizine does not appreciably prolong the QT interval on ECG at high serum levels.
-
TOXICITY ALERT: Overdoses of cetirizine products that also contain pseudoephedrine (e.g., Zyrtec-D 12 Hour) are highly dangerous and potentially fatal. Immediate veterinary intervention and consultation with an animal poison control center are required.
可用產品
劑型
- Oral Tablets (film-coated)
- Chewable Tablets
- Oral Syrup
- Extended-Release Tablets (with Pseudoephedrine - CONTRAINDICATED IN PETS)
獸醫用
- None (No veterinary-labeled products available)
人用標示
- Cetirizine HCl Oral Tablets (film-coated): 5 mg & 10 mg (Zyrtec, generic)
- Cetirizine HCl Chewable Tablets (grape flavor): 5 mg & 10 mg (Zyrtec)
- Cetirizine HCl Oral Syrup: 1 mg/mL in 118 & 473 mL (Zyrtec, generic)
- Cetirizine HCl 5 mg with Pseudoephedrine HCl 120 mg Extended-Release Tablets (Zyrtec-D 12 Hour) - DO NOT USE IN PETS
各地核准狀態
Available as an over-the-counter human medication.
GSL (General Sales List) - available over the counter.
暫無法規資料: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Tablets should be stored at 20-25°C (68-77°F); excursions are permitted to 15-30°C (59-86°F). The oral syrup may be stored at room temperature or in the refrigerator.
飼主須知
西替利嗪 (Cetirizine) 是一種抗組織胺藥，常被用來幫助控制寵物的過敏性皮膚病、搔癢，有時也用於呼吸道過敏。
- 給藥方式：可與食物一起或空腹餵食。如果您的寵物服藥後嘔吐，下次可以嘗試與少量零食或正餐一起餵食。
- 副作用：通常耐受性極佳。偶爾可能出現輕微嗜睡、流口水或嘔吐。如果您的寵物顯得過度昏睡，請聯繫您的獸醫師。
-
嚴重警告：只能使用純西替利嗪成分的產品。絕對不可給您的寵物服用「Zyrtec-D」或任何含有偽麻黃鹼 (Pseudoephedrine) 等鼻塞解除劑的產品。這些成分對犬貓具有極高毒性，甚至可能致命。
- 過敏測試：如果您的寵物安排了過敏原皮膚測試，請事先詢問獸醫師應提前多久停用此藥物，以免影響測試結果。
- 費用：雖然有學名藥可供選擇，但其價格可能比 Benadryl 等老一代抗組織胺藥物稍高。
VetSheet 藥物參考供持牌獸醫專業人員作臨床決策輔助之用，不能取代專業判斷或廠方最新藥品說明書。