Aminophylline
Aminophylline is a methylxanthine bronchodilator used primarily in the treatment of **small airway disease**. It is a stable mixture of theophylline and ethylenediamine (100 mg of aminophylline is equivalent to 79 mg of theophylline). The drug has a **low therapeutic index** and should be dosed on a lean body weight basis. > **Clinical Warning:** Administer with extreme caution in patients with severe cardiac disease, gastric ulcers, hyperthyroidism, renal or hepatic disease, severe hypoxia, or severe hypertension.
Mecanismo: 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.
Dosificación por especie
- 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
Las dosis son una referencia clínica para médicos veterinarios. Confirme siempre con la información vigente del producto y el paciente individual.
Vías de administración
Contraindicaciones
- Patients with a known history of arrhythmias
- Patients with a known history of seizures
Efectos adversos
- 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)
Interacciones farmacológicas
- 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
Monitoreo
- 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)
Sobredosis
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.
La referencia de fármacos de VetSheet está destinada a médicos veterinarios como apoyo a la decisión clínica; no sustituye el juicio profesional ni la información vigente del fabricante.