硫酸鎂 (愛普森鹽)
**硫酸鎂**（通常稱為**愛普森鹽**）在獸醫學中具有多種用途，可用於全身性或局部性疾病。 * **全身性用途：** 靜脈注射用於治療低鎂血症、處理危及生命的心律不整（如尖端扭轉型室性心動過速），並在特定中毒或疾病中作為肌肉鬆弛劑或抗驚厥藥。 * **胃腸道用途：** 口服時，它作為一種強效的滲透性瀉藥，有助於清理腸道。 * **局部用途：** 經常作為高滲透壓浸泡液或敷藥，用於引流局部感染、舒緩肌肉痠痛或治療大型動物的蹄部膿腫。 > **臨床要點：** 雖然非常有效，但全身性給藥需要仔細監測心血管和呼吸狀態，因為高劑量有引起嚴重中樞神經系統和呼吸抑制的風險。
作用機制: Magnesium is a critical intracellular cation and a cofactor for over 300 enzymatic reactions. * **Neuromuscular & CNS:** Magnesium competes with calcium at the motor endplate, decreasing acetylcholine release and reducing motor nerve impulse transmission, leading to muscle relaxation and CNS depression. * **Cardiovascular:** Acts as a physiological calcium channel blocker, slowing sinoatrial node impulse formation and prolonging conduction time → **antiarrhythmic effect**. * **Gastrointestinal:** Poorly absorbed in the GI tract, it creates an osmotic gradient that draws water into the intestinal lumen → **osmotic cathartic effect**. * **Topical:** Creates a hypertonic environment that draws out fluid and exudate from localized swellings or abscesses.
給藥途徑
禁忌症
- Renal failure or severe renal impairment
- Heart block or significant myocardial damage
- Myasthenia gravis (can exacerbate weakness)
- Heart block
- Myocardial damage
- Renal impairment
- Renal failure
不良反應
- Hypermagnesemia
- Muscle weakness
- Respiratory depression
- Hypotension
- Cardiac arrhythmias or heart block
- Diarrhea (with oral administration)
- Somnolence
- CNS depression
- Coma
- Muscular weakness
- Bradycardia
- Prolonged Q-T intervals
- Neuromuscular blockade
- Cardiac arrest
藥物相互作用
- Neuromuscular blocking agents · Potentiates neuromuscular blockade
- CNS depressants · Additive CNS depression
- Calcium channel blockers · Risk of profound hypotension and cardiovascular collapse
- Barbiturates · Additive CNS depression effects · moderate
- General anaesthetics · Additive CNS depression effects · moderate
- Non-depolarizing neuromuscular blocking agents · Risk of severe neuromuscular blockage · major
- Digitalis glycosides · Serious conduction disturbances can occur · major
監測
- Serum magnesium concentrations
- Electrocardiogram (ECG)
- Respiratory rate and depth
- Deep tendon reflexes (e.g., patellar reflex)
- Renal function (BUN, creatinine)
- Blood pressure
- Serum magnesium levels
- ECG (for Q-T interval and heart rate)
- Respiratory rate and effort
- Renal function
過量
Signs of **hypermagnesemia** (magnesium toxicity) include loss of deep tendon reflexes, severe muscle weakness, hypotension, respiratory depression, heart block, and potentially cardiac arrest. > **Treatment:** Discontinue administration immediately. Administer **intravenous calcium** (e.g., calcium gluconate 10%) slowly to antagonize the cardiovascular and neuromuscular effects. Provide respiratory support (intubation and ventilation) and fluid therapy as needed.
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。