氨茶鹼
氨茶鹼是一種甲基黃嘌呤類支氣管擴張劑，主要用於治療**小氣道疾病**。它是茶鹼和乙二胺的穩定混合物（100毫克氨茶鹼相當於79毫克茶鹼）。本藥具有**低治療指數**，必須根據瘦體重謹慎給藥。 > **臨床警告：** 對於患有嚴重心臟病、胃潰瘍、甲狀腺功能亢進、肝腎疾病、嚴重缺氧或嚴重高血壓的病患，應謹慎使用。
作用機制: Aminophylline acts via multiple pharmacological pathways: * **Inhibition of phosphodiesterase (PDE)** → increased intracellular cAMP. * Alteration of intracellular calcium levels. * Release of endogenous catecholamines. * **Antagonism of adenosine and prostaglandin receptors**. These mechanisms collectively lead to **bronchodilation**, enhanced mucociliary clearance, stimulation of the respiratory centre, increased sensitivity to PaCO2, increased diaphragmatic contractility, stabilization of mast cells, and a mild inotropic and diuretic effect.
各物種劑量
- Bronchodilation · 5 mg/kg · PO · q12h
- Emergency bronchodilation · 2-5 mg/kg · IV · single dose · Administer slowly and diluted
- Bronchodilation · 10 mg/kg · PO · q8h · Or slowly i.v. (diluted) for emergency bronchodilation
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。
給藥途徑
禁忌症
- Patients with a known history of arrhythmias
- Patients with a known history of seizures
不良反應
- Vomiting
- Diarrhoea
- Polydipsia (PD)
- Polyuria (PU)
- Reduced appetite
- Tachycardia
- Arrhythmias
- Nausea
- Twitching
- Restlessness
- Agitation
- Excitement
- Convulsions
- Hyperaesthesia (especially in cats)
- Intense local pain (if given IM)
藥物相互作用
- Cimetidine · May increase serum levels of aminophylline · major
- Diltiazem · May increase serum levels of aminophylline · moderate
- Erythromycin · May increase serum levels of aminophylline · moderate
- Fluoroquinolones · May increase serum levels of aminophylline · moderate
- Allopurinol · May increase serum levels of aminophylline · moderate
- Phenobarbital · May decrease the serum concentration of aminophylline · moderate
- Pancuronium · Aminophylline may decrease the effects of pancuronium · moderate
- Beta-adrenergic blockers (e.g., propranolol) · May antagonize each other's effects · moderate
- Halothane · Increased incidence of cardiac dysrhythmias · major
- Ketamine · Increased incidence of seizures · major
監測
- Plasma aminophylline levels (Therapeutic range: 5-20 μg/ml)
- Heart rate and rhythm (ECG if arrhythmias suspected)
- CNS signs (agitation, twitching, seizures)
- Clinical response (respiratory rate and effort)
過量
Overdose is directly related to toxic serum concentrations. Clinical signs of toxicity include severe vomiting, tachycardia, cardiac arrhythmias, extreme agitation, hyperaesthesia (especially in cats), and convulsions/seizures. Treatment is supportive and symptomatic.
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。