米氮平
Mirtazapine
6-azamianserin, Org-3770, mepirzapine
別名: Remeron SolTab · Zispin · Mirataz · 6-azamianserin · Org-3770 · mepirzapine · Mirtazapinum
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
經審核的 v13 劑量證據
結構化劑量計算證據Chemotherapy-induced anorexia
- q24-72h
NA
必須同時考慮的臨床上下文 (2)
- Management of weight loss (label dosage; FDA-approved): Using the transdermal formulation, apply 1.5-inch ribbon (≈2 mg/cat) to the inner pinna of the cat’s ear every 24 hours for 14 days. 1 The person applying medication should wear gloves. Alternate application of ointment between the left and right inner pinnae of the ears.
- ■ This medicine may be given with or without food. If your animal vomits after receiving the medication on an empty stomach, give it with food or a small treat. If vomiting continues, contact your veterinarian.
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
米氮平是一種非典型四環類抗憂鬱藥，在獸醫學中主要被廣泛用作犬貓的強效食慾促進劑和止吐藥。
- 臨床要點：對於患有慢性腎病 (CKD)、鬱血性心衰竭、胃腸道疾病、肝病或腫瘤的病患特別有益，能同時改善噁心與食慾不振。
- 可安全地與其他止吐藥物併用，以治療頑固性嘔吐或化療引起的噁心嘔吐 (CINV)。
- 主要限制劑量的副作用為嗜睡，但在貓咪身上常觀察到矛盾的興奮現象（如異常鳴叫、變得過度親人）。
重要提示：應始終使用最低有效劑量以減少鎮靜副作用。犬隻每日劑量不應超過 30 毫克，因為較高劑量反而會失去促進食慾的效果。
作用機制
Mirtazapine has a complex, multi-receptor pharmacological profile (often classified as a NaSSA - Noradrenergic and Specific Serotonergic Antidepressant):
- Central pre-synaptic α2-adrenergic receptors: Antagonism blocks the negative feedback loop → increases Norepinephrine (NE) release → stimulates appetite via other α-receptors.
- 5-HT3 receptors: Potent antagonism in the Chemoreceptor Trigger Zone (CRTZ) and GI tract → provides robust anti-nausea and antiemetic effects.
- 5-HT2 receptors: Antagonism contributes to its anxiolytic profile.
- H1 (Histamine) receptors: Potent antagonism → produces prominent sedative effects.
- Peripheral α1-adrenergic & Muscarinic receptors: Moderate antagonism → may cause occasional orthostatic hypotension and mild anticholinergic effects.
安全性與警告
禁忌症
- Hypersensitivity to mirtazapine
- Use of monoamine oxidase inhibitors (MAOIs, e.g., selegiline) within the past 14 days
- Pre-existing haematological disease
不良反應
- Drowsiness/sedation
- Increased affection (cats)
- Hypotension
- Tachycardia
- Sedation (common and can be profound)
- Increased vocalization (especially in cats)
- Altered behavior and increased interaction with others
- Blood dyscrasias (reported in humans)
注意事項
Use with caution in patients with known cardiac disease or cerebrovascular disease that could be exacerbated by hypotension.
- Monitor patients with renal impairment, renal failure, or hepatic disease closely, as clearance may be reduced.
- Use with caution in patients with diabetes mellitus, as antidepressants may indirectly affect blood glucose concentrations.
- Due to weak anticholinergic activity, use vigilance in patients susceptible to these effects (e.g., urinary retention, prostatic hypertrophy, acute closed-angle glaucoma, increased intraocular pressure, GI obstruction, or ileus).
- May impair concentration and alertness in active animals.
- Use cautiously in patients with pre-existing hematological disease (leukopenia, neutropenia, thrombocytopenia), as it has been rarely associated with blood dyscrasias in humans.
藥物相互作用
Mirtazapine may cause increases in blood pressure
Minimal effects on mirtazapine blood levels, but may cause additive impairment of motor skills
May cause increased serum concentrations of mirtazapine
Increased risk for serotonin syndrome
Increased risk for serotonin syndrome; MAO inhibitors considered contraindicated with mirtazapine
Increased risk for serotonin syndrome
Increased risk of serotonin syndrome
監測
- Increased appetite
- Decreased episodes of vomiting
- Weight gain
- Adverse effects (sedation, vocalization, tachycardia)
- Appetite and body weight
- Behavioral changes (sedation, vocalization)
- Complete blood count (due to human risk of blood dyscrasias)
- Hepatic and renal function parameters
藥物動力學
半衰期
吸收
Rapidly and completely absorbed following oral administration. Food has minimal effects on rate and extent of absorption. Oral bioavailability is about 20% for dogs and 50% for humans.
分佈
Plasma protein binding is approximately 70-72% for dogs, mice, and rats.
代謝
Metabolized via multiple pathways including 8-hydroxylation, N-oxidation, and demethylation followed by conjugation. Cats have a limited capacity for glucuronidation, leading to less rapid clearance and requiring extended dosing intervals.
排除
Elimination occurs primarily via urine (75%) and feces (15%). Renal or hepatic impairment may reduce clearance.
過量
Ingestion of upwards of 10-fold to 30-fold the therapeutic dose in humans exhibits minimal toxicity requiring no acute intervention other than observation.
Treatment: Despite the wide safety margin, standard overdose protocols (including the administration of activated charcoal) and monitoring are recommended in acute overdose situations.
可用產品
劑型
- Oral Tablets
- Orally Disintegrating Tablets (ODT)
- 15 mg tablets
- 15 mg/ml oral solution
- Transdermal formulation (named patient basis / authorized veterinary preparations)
獸醫用
- None
- Mirataz 20 mg/g transdermal ointment
人用標示
- Mirtazapine Oral Tablets: 7.5 mg, 15 mg, 30 mg & 45 mg (Remeron, generic)
- Mirtazapine Orally Disintegrating Tablets: 15 mg, 30 mg & 45 mg (Remeron SolTab, generic)
- Zispin 15 mg tablets
- Zispin 15 mg/ml oral solution
各地核准狀態
Mirataz transdermal ointment is authorized for cats.
Mirataz transdermal ointment is authorized for cats.
暫無法規資料: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Store coated and orally disintegrating tablets at 25°C (77°F) with excursions permitted to 15-30°C (59-86°F). Protect from light and moisture. Orally disintegrating tablets should be used immediately once removed from the blister pack.
飼主須知
- 給藥方式：請嚴格按照處方劑量給藥。可與食物一起或空腹給予。
- 口腔崩解錠 (ODT)：若使用口含融化錠，請確保雙手完全乾燥。將藥片放在寵物舌下，並合上其嘴巴數秒直到藥片溶解。溶解後請立即提供飲水。
- 預期效果：您應會觀察到寵物食慾改善且嘔吐減少。
- 需回報的副作用：若發現寵物過度嗜睡、嚴重虛弱、心跳過快或行為異常，請聯繫您的獸醫師。
貓咪飼主注意事項：貓咪服藥後變得異常愛叫（大聲喵喵叫）或過度黏人是非常常見的現象。這通常是無害的，但若造成困擾，請告知您的獸醫師。
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