派醋甲酯 / 甲基芬尼達
Methylphenidate
Methylphenidate Hydrochloride
別名: Concerta · Metadate · Methylin · Daytrana · Focalin · Equasym · Attenta · Rilatine · Riphenidate · Ritalina · Ritaline · Ritaphen · Rubifen · Tranquilyn
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 |
|---|---|---|---|---|---|
| Treatment of narcolepsy/cataplexy | 5-10 mg (total dose) | PO | once daily | — | 🌎 NA |
| Treatment of narcolepsy/cataplexy (to supplement imipramine) | 0.25-0.5 mg/kg or 5-10 mg (total dose) | PO | q12-24h | — | 🌎 NA |
| Diagnosis and treatment of hyperkinesis | 5-20 mg (total dose) | PO | q8-12h | 3 days | 🌎 NA |
| Hyperkinesis-hyperactivity | Small dogs: 5+ mg total dose; Large Dogs: 20-40 mg total dose | PO | q12h | — | 🌎 NA |
- Treatment of narcolepsy/cataplexy (to supplement imipramine): Used to supplement imipramine given at 0.5-1 mg/kg PO q8-12h
- Diagnosis and treatment of hyperkinesis: Give for 3 days and assess for improvement of target behaviors (anxiety, overactivity, learning ability)
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
派醋甲酯（Methylphenidate）是一種中樞神經系統（CNS）興奮劑，其結構和藥理作用與安非他命相似。在獸醫學中，主要用於標示外使用（off-label use），以診斷和控制犬隻的猝睡症/猝倒症（narcolepsy/cataplexy）及過動症（hyperkinesis）。
除了中樞神經作用外，它具有微弱的擬交感神經活性，但在標準治療劑量下對周邊循環的影響極小。
臨床要點：由於派醋甲酯在美國屬於第二級（C-II）管制藥品，具有嚴格的處方規定以及極高的人類濫用風險。獸醫師在開立處方和配藥時，必須採取適當的法律與道德防範措施。
作用機制
Methylphenidate acts primarily as a norepinephrine-dopamine reuptake inhibitor (NDRI).
- It binds to and blocks the dopamine transporter (DAT) and norepinephrine transporter (NET) on presynaptic neurons.
- Blockade of these transporters → prevents the reuptake of monoamines → increases the concentration of dopamine and norepinephrine in the extraneuronal space (synaptic cleft).
- This amplified monoamine signaling in the brainstem arousal system and cerebral cortex leads to increased alertness, focus, and CNS stimulation.
安全性與警告
禁忌症
- Seizure disorders
- Cardiac disease or hypertension
- Aggressive animals
不良反應
- Tachycardia (increased heart rate)
- Tachypnea (increased respiratory rate)
- Anorexia
- Tremors
- Hyperthermia (particularly exercise-induced)
注意事項
Use with extreme caution in dogs with pre-existing seizure disorders, cardiac disease, hypertension, or those exhibiting aggressive behavior. Methylphenidate is a Class-II controlled substance with a high potential for human abuse; prescribe and dispense with strict adherence to controlled substance regulations.
藥物相互作用
Methylphenidate may increase serum levels of these anticonvulsants
Rare cases of cardiovascular effects (including death) reported in humans; mechanism unknown
Methylphenidate may reduce the efficacy of hypotensive effects
Concurrent use could lead to a severe hypertensive crisis
Methylphenidate may inhibit SSRI metabolism and increase their serum levels
Methylphenidate may inhibit TCA metabolism and increase their serum levels
Methylphenidate may inhibit warfarin metabolism and increase INR
監測
- Clinical efficacy (improvement in target behaviors or narcoleptic episodes)
- Vital signs (heart rate, respiratory rate)
- Body weight (monitor for anorexia/weight loss)
- Periodic CBC with differential and platelet counts (recommended during prolonged therapy based on human guidelines)
藥物動力學
半衰期
吸收
Dogs: Immediate-release tablets peak in ~15 minutes. Sustained-release tablets peak in ~30 minutes but with much lower peak concentrations. Humans: Rapidly and well absorbed from the GI tract; food may increase the rate but not the extent of absorption. Peak levels occur ~2 hours post-dose.
分佈
Humans: Protein binding is low.
代謝
Humans: Extensively metabolized during the first-pass effect.
排除
Humans: Less than 1% is excreted unchanged in the urine. Clearance in dogs is rapid (0.27 L/hr for IR, 0.97 L/hr for SR).
過量
Toxicity can occur at relatively low doses in veterinary patients.
- Dogs: Doses of 1 mg/kg (or below) can cause toxic reactions. One fatality was reported at 3.1 mg/kg, though research dogs have survived 20 mg/kg/day for 90 days.
- Cats: A 5 mg tablet caused severe toxicity (tremors, agitation, mydriasis, tachycardia, tachypnea, hypertension) which resolved after 25 hours with supportive care.
Clinical Signs of Overdose: Primarily CNS over-stimulation and excessive sympathomimetic effects: hyperactivity, salivation, diarrhea, head bobbing, agitation, tachycardia, hypertension, tremors, seizures, and hyperthermia.
Treatment:
- Decontamination: Standard gut detoxification (emesis, activated charcoal, cathartic). Avoid emesis if the animal is already symptomatic due to seizure/aspiration risks.
- Supportive Care:
- Phenothiazines (e.g., acepromazine, chlorpromazine) to control agitation.
- Beta-blockers to manage severe tachycardia.
- External cooling for hyperthermia.
- Cyproheptadine may be administered to help prevent or treat serotonin syndrome.
可用產品
劑型
- Oral tablets
- Chewable tablets
- Extended-release tablets
- Extended-release capsules
- Oral solution
- Transdermal patch
人用標示
- Methylphenidate Oral Tablets: 5 mg, 10 mg & 20 mg
- Chewable Tablets: 2.5 mg, 5 mg & 10 mg
- Extended-Release Tablets: 10 mg, 18 mg, 20 mg, 27 mg, 36 mg & 54 mg
- Extended-Release Capsules: 20 mg, 30 mg, 40 mg, 50 mg & 60 mg
- Methylphenidate Oral Solution: 5 mg/5 mL & 10 mg/5 mL
- Methylphenidate Transdermal Patch: 10 mg/9 h, 15 mg/9 h, 20 mg/9 h & 30 mg/9 h
各地核准狀態
暫無法規資料: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Unless otherwise noted on the label, methylphenidate tablets and extended-release tablets/capsules should be stored in tight, light-resistant containers at room temperature.
飼主須知
- 安全存放：本藥物為管制藥品，具有極高的人類濫用風險。請務必將其安全存放在上鎖的櫥櫃或安全的地方。
- 給藥方式：如果您的寵物被處方的是長效型（緩釋）錠劑或膠囊，請勿將其壓碎或咀嚼；必須整顆吞服。
- 監測：密切觀察您的寵物是否有過度興奮的跡象，例如心跳加快、呼吸急促、焦躁不安、發抖或食慾不振。若出現任何上述症狀，請立即聯絡您的獸醫師。
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