VetSheet

貝膽鹼

Bethanechol

Bethanechol chloride

膽鹼能藥物（毒蕈鹼受體激動劑）POSCIV (emergencies only)IM (not recommended)

別名: Urecholine · Myotonine · Bethanechol chloride · Betanecol

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

各物種劑量

此藥的劑量資料尚未收錄於 VetSheet 藥典，以下其他章節資料完整。開立處方前請參閱最新仿單。

概覽

​貝膽鹼 (Bethanechol)​ 是一種合成的膽鹼酯，屬於直接作用的副交感神經致效劑（膽鹼能藥物）。

  • ​主要獸醫用途​：主要用於刺激小動物的膀胱收縮，是治療​逼尿肌無力​（膀胱鬆弛、過度擴張且無法正常收縮）的首選藥物。這種情況通常繼發於嚴重的膀胱過度擴張或神經系統疾病（如下運動神經元病變）。
  • ​臨床要點​：在刺激膀胱收縮之前，確保尿道括約肌放鬆至關重要。因此，貝膽鹼經常與 α-1 拮抗劑（如 prazosin 或 phenoxybenzamine）或骨骼肌鬆弛劑（如 diazepam）合併使用，以防止膀胱破裂。
  • ​胃腸道用途​：過去曾用作食道或一般胃腸道刺激劑，但目前這些用途已大多被 metoclopramide 和 neostigmine 所取代。
  • ​藥理特性​：它對乙醯膽鹼酯酶的分解具有高度抵抗力，因此與天然乙醯膽鹼相比，其作用時間顯著更長。

作用機轉

Bethanechol directly stimulates muscarinic (M) cholinergic receptors, with a strong affinity for the M3 receptors located on the smooth muscle of the detrusor (bladder wall) and gastrointestinal tract.

  • Mechanism Pathway: Binds to M3 receptor → activates Gq-protein → stimulates Phospholipase C (PLC) → increases Inositol triphosphate (IP3) and Diacylglycerol (DAG) → triggers release of intracellular calcium (Ca2+) → smooth muscle contraction.
  • Receptor Specificity: At usual therapeutic doses, it has negligible effects on nicotinic receptors, which minimizes skeletal muscle and ganglionic side effects.
  • Physiological Effects: Increases detrusor muscle tone, decreases bladder capacity, increases GI peristalsis, and increases gastric/pancreatic secretions.

安全性與警告

禁忌症

  • Bladder neck or urinary outflow obstruction
  • Questionable bladder wall integrity (e.g., recent bladder surgery)
  • Hyperthyroidism
  • Peptic ulcer disease or inflammatory GI lesions
  • Recent GI surgery with resections/anastomoses
  • GI obstruction or peritonitis
  • Hypersensitivity to bethanechol
  • Epilepsy
  • Asthma
  • Coronary artery disease or occlusion
  • Hypotension
  • Severe bradycardia
  • Vagotonia or vasomotor instability

不良反應

  • Salivation
  • Lacrimation
  • Urination
  • Defecation
  • Vomiting
  • Diarrhea
  • Anorexia
  • Bradycardia (high dose/SC)
  • Arrhythmias (high dose/SC)
  • Hypotension (high dose/SC)
  • Asthma/Dyspnea (high dose/SC)
  • Abdominal pain (horses)

注意事項

Important Outflow Warning: If urinary outflow resistance is increased due to enhanced urethral tone (not mechanical obstruction), bethanechol should only be used in conjunction with another agent that will sufficiently reduce outflow resistance (e.g., diazepam, dantrolene for striated muscle, or phenoxybenzamine for smooth muscle).

  • Route Warnings: IM or IV use is not recommended except in emergencies when the IV route may be used. Severe cholinergic reactions are likely if given IV.
  • Antidote Readiness: If injecting the drug (SC or IV), it is highly recommended that atropine be immediately available to treat potential cholinergic crisis.

藥物交互作用

Anticholinergic drugs (e.g., atropine, glycopyrrolate, propantheline)

Can antagonize bethanechol's effects

Other cholinergic drugsMajor

Additive toxicity and increased risk of cholinergic crisis

AtropineModerate

Antagonizes the effects of bethanechol

監測

  • Clinical efficacy (successful urination, reduction in residual bladder volume)
  • Signs of cholinergic toxicity (SLUD: salivation, lacrimation, urination, defecation)
  • Heart rate and rhythm (if given parenterally)

藥物動力學

吸收

Poorly absorbed from the GI tract. Onset of action is usually within 30-90 minutes after oral dosing. After subcutaneous administration, effects begin within 5-15 minutes and usually peak within 30 minutes. Duration of action after oral dosing may persist up to 6 hours after large doses, and 2 hours after SC dosing.

分佈

Does not enter the CNS after usual doses; other distribution aspects are not known. It is unknown if bethanechol is distributed into milk.

代謝

The metabolic fate of bethanechol has not been described.

排除

The excretory fate of bethanechol has not been described.

過量

Clinical signs of overdosage are basically cholinergic in nature.

  • Mild/Moderate Toxicity: Muscarinic effects (salivation, urination, defecation, vomiting) are usually seen with oral or SC administration.
  • Severe Toxicity: If given IM or IV, a full-blown cholinergic crisis can occur, characterized by circulatory collapse, bloody diarrhea, shock, and possible cardiac arrest.
  • Treatment: Atropine is the specific antidote for bethanechol toxicity. Epinephrine may also be employed to treat clinical signs of severe bronchospasm.

可用產品

劑型

  • Tablets
  • Injection

人用標示

  • Urecholine®

各地核准狀態

European Union✓ 已核准處方藥EMA

POM (Prescription Only Medicine)

United Kingdom✓ 已核准處方藥VMD

POM (Prescription Only Medicine)

暫無法規資料: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU

飼主須知

​重要提示​：貝膽鹼有助於寵物的膀胱肌肉收縮，使其能夠正常排尿。通常用於膀胱過度擴張或肌肉無力的情況。

  • ​給藥方式​：請嚴格按照處方給藥。未經獸醫同意，請勿自行增加劑量。
  • ​注意事項​：因為此藥物會刺激「休息與消化」系統，您可能會注意到一些副作用，通常以 SLUD（流涎、流淚、排尿、排便）來概括。也可能出現輕微的嘔吐或腹瀉。
  • ​何時應聯繫獸醫​：如果您的寵物出現嚴重嘔吐、腹瀉、過度流口水、呼吸困難或顯得異常虛弱，請立即聯繫您的獸醫。
  • ​安全警告​：如果您的寵物有排尿動作但無法排出尿液（尿道阻塞），絕對不能給予此藥物，因為在阻塞的情況下強迫膀胱收縮可能會導致嚴重的損傷或膀胱破裂。

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