アミノフィリン
アミノフィリンは、主に**小気道疾患**の治療に使用されるメチルキサンチン系気管支拡張薬です。テオフィリンとエチレンジアミンの安定した混合物です（アミノフィリン100mgはテオフィリン79mgに相当）。**治療域が狭い**ため、除脂肪体重に基づいて慎重に投与する必要があります。 > **臨床的警告：** 重度の心疾患、胃潰瘍、甲状腺機能亢進症、肝・腎疾患、重度の低酸素症、または重度の高血圧の患者には慎重に投与してください。
作用機序: 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.
動物種別の用量
- 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
用量は獣医療従事者向けの臨床リファレンスです。必ず最新の添付文書と個々の患者で確認してください。
投与経路
禁忌
- Patients with a known history of arrhythmias
- Patients with a known history of seizures
有害事象
- 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)
薬物相互作用
- 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
モニタリング
- 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)
過量投与
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 の薬剤リファレンスは、獣医療従事者向けの臨床意思決定支援を目的としており、専門的判断やメーカーの最新添付文書に代わるものではありません。