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嗎啡

Morphine

Morphine sulfate

鴉片類促效劑 / 鎮痛藥IVIMSCEpiduralSpinalIntra-articularPORectal狗貓小型哺乳類馬豬羊山羊

別名: Astramorph PF · Avinza · DepoDur · Infumorph · Kadian · MSIR · MS Contin · Oramorph SR · RMS · Roxanol · Morphini sulfas · Morphine sulfate · Morphine hydrochloride

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

Analgesia (extra-label) — CRI dosing

0.05–0.1 mg/kg/mg/kg/hIV

須由已驗證獸醫確認

NA

必須一併考量的臨床脈絡 (5)
  • 1. Preservative-free morphine formulations should be used for epidural administration.
  • 2. Do not confuse CRI dosages listed as mg/kg/hour with those listed as µg/kg/minute.
  • 3. For additional dosages/protocols for using morphine in combination with other drugs (eg, ketamine, lidocaine, dexmedetomidine) for pain/sedation in dogs or cats, see the dosages and their accompanying references in the Dexmedetomidine, Ketamine, and Lidocaine monographs.
  • Analgesia (extra-label):
  • Morphine injection should be stored at room temperature (20°C-25°F [68°F-77°F]), protected from light; do not freeze. 19 Morphine gradually darkens in color when exposed to light. Morphine does not appear to adsorb to plastic or polyvinyl chloride (PVC) syringes, tubing, or bags.
管制藥物須由已驗證獸醫確認formulary方案年份 2023審核 dose-audit-plumb-v13

劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。

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概覽

嗎啡是獸醫學中用於治療中度至重度急性疼痛的典型​鴉片類鎮痛藥​。它是一種源自鴉片的天然純粹 mu-鴉片受體促效劑。

​臨床要點與物種差異：​

  • ​狗與靈長類：​ 嗎啡通常會引起可預期的中樞神經系統抑制、鎮靜和鎮痛。由於直接刺激化學受體觸發區 (CTZ)，它對狗是一種強效催吐劑。狗在首次給藥後通常會立即排便，隨後腸胃蠕動減少。
  • ​貓、馬與反芻動物：​ 這些物種可能會表現出矛盾的​中樞神經系統興奮​（煩躁、狂躁、踱步）而非抑制，特別是在沒有同時使用鎮靜劑或鎮定劑（如 acepromazine 或 alpha-2 促效劑）的情況下。貓需要比狗高得多的劑量才會引發嘔吐。
  • ​組織胺釋放：​ 嗎啡會引起肥大細胞非免疫性組織胺釋放。靜脈注射必須緩慢進行，以避免嚴重的低血壓、血管擴張和支氣管收縮。
  • ​體溫調節：​ 嗎啡會導致狗和兔子體溫過低，但會導致貓、馬、牛和羊體溫過高。

作用機轉

Morphine acts primarily as a full agonist at the mu (μ) opioid receptors in the central nervous system, with some secondary activity at delta receptors.

  • ​Mechanism:​ Binding to the G-protein coupled mu-receptor → inhibits adenylate cyclase → decreases intracellular cAMP.
  • ​Presynaptic effect:​ Closes voltage-gated calcium channels → decreases the release of excitatory nociceptive neurotransmitters (e.g., Substance P, glutamate).
  • ​Postsynaptic effect:​ Opens inward-rectifying potassium channels → hyperpolarizes the neuron → inhibits ascending pain transmission pathways.
  • ​Secondary effects:​ Direct stimulation of the ​chemoreceptor trigger zone (CTZ)​ causes emesis. Central vagal stimulation leads to bradycardia. Increased anti-diuretic hormone (ADH) release can reduce urine production.

安全性與警告

禁忌症

  • Hypersensitivity to narcotic analgesics
  • Patients receiving monoamine oxidase inhibitors (MAOIs)
  • Diarrhea caused by a toxic ingestion (until toxin is eliminated)
  • Scorpion envenomation (Centruroides spp. - potentiates venom)
  • Conditions where vomiting is contraindicated (e.g., raised intraocular pressure)

不良反應

  • Histamine release (hypotension, vasodilation)
  • Bronchoconstriction
  • CNS depression (dogs, primates) or excitation (cats, horses, ruminants)
  • Physical dependence (with chronic use)
  • Hyperthermia (cattle, goats, horses, cats)
  • Hypothermia (dogs, rabbits)
  • Nausea and vomiting
  • Decreased intestinal peristalsis and constipation
  • Initial defecation (dogs)
  • Panting (dogs)
  • Bradycardia or tachycardia
  • Histamine release (if given rapidly IV)
  • Vomiting (common in non-painful pre-operative patients)
  • Transient excitation (IV administration)
  • Respiratory depression (especially under general anaesthesia)
  • Constriction of gastrointestinal sphincters (e.g., pyloric sphincter)
  • Reduction in gastrointestinal motility (with prolonged use)
  • Neonatal sedation (crosses the placenta)

注意事項

​Extreme Caution:​ Patients with head injuries, increased intracranial pressure, acute abdominal conditions (e.g., colic - may mask clinical signs), and respiratory disease or acute respiratory dysfunction.

​Caution:​ Hypothyroidism, severe renal insufficiency (acute uremia), adrenocortical insufficiency (Addison's), and geriatric or severely debilitated patients.

​Important Notes:​

  • ​IV Administration:​ Must be given slowly to avoid significant hypotension and histamine release.
  • ​Envenomation:​ Avoid in envenomation situations, as clinical signs associated with histamine-release can be confused with anaphylaxis.
  • ​Uremia:​ Because of its effects on vasopressin (ADH), urine flow can decrease by up to 90% in dogs given large doses.

藥物交互作用

CNS Depressants (anesthetics, antihistamines, phenothiazines, barbiturates)

May cause increased CNS or respiratory depression when used with morphine.

Diuretics

Opiates may decrease diuretic efficacy in congestive heart failure patients.

Monoamine Oxidase Inhibitors (MAOIs, e.g., amitraz, selegiline)

Use with extreme caution; contraindicated in humans due to risk of severe opiate overdose signs.

Skeletal Muscle Relaxants

Morphine may enhance neuromuscular blockade.

Tricyclic Antidepressants (clomipramine, amitriptyline)

Morphine may exacerbate the effects of tricyclic antidepressants.

Warfarin

Opiates may potentiate anticoagulant activity.

CNS depressants (anaesthetics, antihistamines, barbiturates, phenothiazines, tranquillizers)Major

Increased CNS or respiratory depression

監測

  • CNS level of depression or excitation
  • Blood pressure (especially with IV use)
  • Analgesic activity
  • Respiratory rate and depth (especially under general anaesthesia)
  • Pain scores (to assess individual efficacy)
  • Signs of histamine release (hypotension, tachycardia) during IV administration
  • Gastrointestinal motility

藥物動力學

半衰期

貓~3 hours馬88 minutes (IV)狗~1 hour

吸收

Absorbed when given by IV, IM, SC, and rectal routes. Very low oral bioavailability (<20%) in dogs due to a high first-pass effect, limiting the clinical usefulness of oral morphine in canines.

分佈

Concentrates in the kidney, liver, and lungs; lower levels are found in the CNS. The majority of free morphine is found in skeletal muscle. Crosses the placenta and distributes into maternal milk. Volume of distribution in dogs is ~7.5 L/kg.

代謝

Major route of elimination is by metabolism in the liver, primarily by glucuronidation. Cats are deficient in this metabolic pathway, leading to prolonged half-lives.

排除

The active glucuronidated metabolite (M6G) is excreted by the kidney. Clearance in dogs is approximately 83 mL/min/kg.

過量

​Signs of Toxicity:​ Overdosage may produce profound respiratory and/or CNS depression in most species. Newborns are more susceptible. Parenteral doses >100 mg/kg are thought to be fatal in dogs. Other toxic effects include cardiovascular collapse, hypothermia, and skeletal muscle hypotonia. Horses, cats, swine, and cattle may demonstrate CNS excitability (hyperreflexia, tremors) and seizures at high doses or if given rapidly intravenously.

​Treatment:​

  • Naloxone is the agent of choice for treating respiratory depression. Doses may need to be repeated as naloxone's effects might diminish before sub-toxic levels of morphine are attained.
  • Mechanical respiratory support should be considered in severe cases.
  • Pentobarbital has been suggested for CNS excitement and seizures in cats, but extreme caution is required as barbiturates and narcotics have additive respiratory depressant effects.

可用產品

劑型

  • Morphine Sulfate for Injection (1-50 mg/mL)
  • Liposomal Extended-release Injection (10 mg/mL)
  • Preservative-free Injection (0.5-25 mg/mL)
  • Soluble Tablets for Injection
  • Oral Tablets (15 mg, 30 mg)
  • Extended/Controlled Release Tablets (15-200 mg)
  • Extended/Sustained Release Capsules (20-200 mg)
  • Oral Solution (2-20 mg/mL)
  • Rectal Suppositories (5-30 mg)
  • Injectable solution: 10 mg/ml, 15 mg/ml, 20 mg/ml, 30 mg/ml
  • Oral tablets: 10 mg, 30 mg, 60 mg, 100 mg
  • Oral suspensions
  • Slow-release capsules
  • Granules

人用標示

  • Morphine Sulfate for Injection (1 mg/mL to 50 mg/mL)
  • Morphine Sulfate Liposomal Extended-release Injection (DepoDur, 10 mg/mL)
  • Morphine Sulfate for Injection, preservative-free (Infumorph, Astramorph PF, 0.5 mg/mL to 25 mg/mL)
  • Morphine Sulfate Soluble Tablets for Injection (10 mg, 15 mg, 30 mg)
  • Morphine Sulfate Oral Tablets (15 mg, 30 mg)
  • Morphine Sulfate Extended/Controlled Release Tablets (MS Contin, Oramorph SR, 15 mg to 200 mg)
  • Morphine Sulfate Extended/Sustained Release Capsules (Avinza, Kadian, 20 mg to 200 mg)
  • Morphine Sulfate Oral Solution (MSIR, Roxanol, 2 mg/mL to 20 mg/mL)
  • Morphine Sulfate Rectal Suppositories (RMS, 5 mg to 30 mg)
  • Morphine sulfate injectable solutions
  • Morphine sulfate tablets and slow-release capsules
  • Morphine suppositories

各地核准狀態

European Union✗ 未核准處方藥 · Schedule 2EMA

Methadone is the licensed alternative preferred for bolus administration.

United Kingdom✗ 未核准處方藥 · POM CD SCHEDULE 2VMD

Controlled Drug Schedule 2. Methadone is the licensed alternative.

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儲存與穩定性

Oral morphine products should be stored in tight, light-resistant containers at room temperature unless otherwise labeled. Morphine injection should be stored at room temperature, protected from light; do not freeze. Morphine gradually darkens in color when exposed to light; protect from prolonged exposure to bright light.

飼主須知

嗎啡是一種強效且受嚴格管制的止痛藥，通常在獸醫直接監督下的醫院環境中給藥。

  • ​預期反應：​ 您的寵物可能會顯得鎮靜、嗜睡或異常安靜。狗經常會嚴重喘氣，並可能在服藥後不久嘔吐或排便。
  • ​貓和馬：​ 有時可能會顯得焦躁不安、來回踱步或睜大眼睛，而不是嗜睡。這是已知的物種差異。
  • ​居家照護：​ 如果您的寵物帶口服嗎啡回家，請務必將其放在兒童和其他動物接觸不到的地方。這是一種受到高度管制的藥物（第二級管制藥品）。未經諮詢獸醫，請勿自行調整劑量。

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