aminophylline: clinical use

Prescribing considerations

• Confirm recent aminophylline or theophylline exposure before treatment.
• Account for smoking changes, acute fever or influenza, influenza vaccination, age, and cardiac, hepatic or renal dysfunction.
• Use particular caution with epilepsy, peptic ulcer disease, hyperthyroidism, glaucoma, diabetes, hypoxaemia, hypertension and impaired cardiac or circulatory function.
• Intravenous administration must be slow; rapid administration increases cardiovascular and central nervous system toxicity.
• Use in infants younger than six months is not recommended because metabolism is highly variable.

Contraindications and cautions

• Hypersensitivity to ethylenediamine, theophyllines, caffeine, theobromine or an excipient.
• Concurrent treatment with another xanthine medicine.
• Acute porphyria.

Monitoring

• Plasma theophylline concentration, particularly during initiation, suspected toxicity, interacting treatment or smoking changes.
• Clinical signs of gastrointestinal, neurological and cardiovascular toxicity.
• Serum potassium, especially with beta-2 agonists, corticosteroids, diuretics, severe asthma or hypoxia.
• More frequent assessment may be needed in older people, pregnancy, heart failure or hepatic impairment.

Clinical pharmacology

Aminophylline is a soluble theophylline–ethylenediamine complex. The active theophylline component is hepatically metabolised, has highly variable clearance, crosses the placenta and enters breast milk; cigarette smoking increases its clearance.

Formulation and product differences

• The selected product is a solution for intravenous injection or infusion rather than an oral modified-release preparation.
• It contains ethylenediamine and water for injections.
• It is unstable in substantially acidic solutions, and alkali-sensitive medicines should not be added to infusion fluids containing it.

Injection

Route: Parenteral

Strengths: 25 mg/mL