新斯狄明
**新斯狄明**是一種可逆的乙醯膽鹼酯酶抑制劑，在獸醫學中主要用於診斷和控制**重症肌無力**，以及拮抗非去極化神經肌肉阻斷劑的作用。由於其極性結構，它對中樞神經系統（CNS）的穿透力較差。 > **臨床警告：** 給藥可能會引發危及生命的**膽鹼能危機**。強烈建議使用與格隆溴銨（glycopyrronium）的複方製劑，或準備好阿托品（atropine）以便立即靜脈注射，以控制嚴重的毒蕈鹼副作用（例如嚴重心搏過緩、心搏停止、支氣管收縮）。
作用機制: Neostigmine acts as a reversible inhibitor of the enzyme **acetylcholinesterase** at the neuromuscular junction (NMJ) and autonomic synapses. Inhibition of **acetylcholinesterase** → Decreased breakdown of **acetylcholine (ACh)** → Accumulation of ACh in the synaptic cleft → Prolonged and enhanced stimulation of **nicotinic** and **muscarinic receptors** → Improved muscle contraction (in myasthenia gravis) and reversal of non-depolarizing neuromuscular blockade.
各物種劑量
- Diagnosis of myasthenia gravis / Antagonism of non-depolarizing neuromuscular block · 0.05 mg total dose (historical) · IV · Single dose · N/A · Historical dose; recent reports indicate this can cause cholinergic crisis. Recommended to use combined formulation with glycopyrronium. Pre-treat with atropine if using for MG diagnosis.
- Diagnosis of myasthenia gravis / Antagonism of non-depolarizing neuromuscular block · 0.05 mg total dose (historical) · IV · Single dose · N/A · Extrapolated from general text. Extreme caution due to risk of feline asthma exacerbation.
劑量為合格獸醫專業人員的臨床參考。請務必對照最新藥品仿單及個別病患確認。
給藥途徑
禁忌症
- Mechanical gastrointestinal obstruction
- Mechanical urinary tract obstruction
- Peritonitis
不良反應
- Nausea and vomiting
- Increased salivation (ptyalism)
- Diarrhoea
- Muscle fasciculations and cramps
- Weakness and paralysis (with overdose)
- Severe bradyarrhythmias or asystole
- Miosis and nystagmus
- Hypotension
- Bronchoconstriction and increased bronchial secretions
藥物相互作用
- Aminoglycosides · May antagonize the neuromuscular effects of neostigmine · moderate
- Clindamycin · May antagonize the neuromuscular effects of neostigmine · moderate
- Halogenated inhalational anaesthetics · May antagonize the neuromuscular effects of neostigmine · moderate
- Quinine and related compounds · May increase clinical severity of myasthenia gravis and reduce neostigmine effectiveness · moderate
- Beta-blockers · May reduce effectiveness in myasthenia gravis; concurrent use may result in severe bradycardia · major
- Suxamethonium · Neostigmine inhibits its metabolism, prolonging and enhancing its clinical effect (combined use not recommended) · major
- Non-depolarizing muscle relaxants · Neostigmine antagonizes their effect (therapeutic use) · major
- Atropine · Antagonizes the muscarinic effects of neostigmine (used therapeutically to manage side effects) · moderate
監測
- Heart rate and rhythm (ECG monitoring recommended during IV administration)
- Respiratory rate, effort, and airway patency
- Signs of cholinergic crisis (excessive salivation, urination, defecation, miosis)
- Muscle strength and fasciculations
過量
**Cholinergic Crisis** can occur with overdosage, presenting with both muscarinic and nicotinic effects (SLUDGE signs: Salivation, Lacrimation, Urination, Defecation, Gastrointestinal distress, Emesis), miosis, bradycardia, hypotension, muscle cramps, fasciculations, weakness, paralysis, bronchoconstriction, ataxia, seizures, and coma. **Management:** * **Maintenance of respiration** is the absolute priority. * Administer **Atropine** to control muscarinic signs (note: atropine does *not* antagonize nicotinic effects like muscle weakness and paralysis). * If muscle twitching is severe, control with small doses of a **competitive neuromuscular blocker**. * The cholinesterase reactivator **pralidoxime** can be used as an adjunct to atropine. * Provide intensive supportive care as required.
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。