Oral Chronic bronchospasm Adult: As hydrate: Initially, 225-450 mg bid, increased if necessary. Intravenous Acute severe bronchospasm Adult: Loading dose: 5 mg/kg (ideal body weight) or 250-500 mg (25 mg/ml) by slow inj or infusion over 20-30 min. Maintenance infusion dose: 0.5 mg/kg/hr. Max rate: 25 mg/min. Elderly: Dose reduction may be ncessary. Hepatic impairment: Dose reduction may be ncessary.
Other xanthines. Clearance reduced by allopurinol, some antiarrhythmics, cimetidine, disulfiram, fluvoxamine, interferon-alpha, macrolide antibiotics, quinolones, oral contraceptives, thiabendazole and viloxazine. Clearance increased by phenytoin, anticonvulsants, ritonavir, rifampicin, sulfinpyrazone, cigarette smoking. Corticosteroids, diuretics, beta2-agonists. Potentially Fatal: Increased risk of cardiac arrhythmias with sympathomimetics and halothane. Tachycardia with pancuronium. beta-blockers inhibit metabolism. Increased risk of convulsion with quinolones, ketamine.
Neonates, elderly, lactation, pregnancy, cardiac/hepatic diseases, peptic ulceration, hyperthyroidism, hypertension, epilepsy, heart failure, chronic alcoholism, acute febrile illness.
Aminophylline is a combination of theophylline and ethylenediamine. Ethylenediamine is inactive; it increases the solubility of theophylline in water. Theophylline relaxes bronchial smooth muscle. Suggested mechanisms are an increase in intracellular cAMP through inhibition of phosphodiesterase; adenosine receptor antagonism, prostaglandin antagonism and effects on intracellular calcium.
Oral Chronic bronchospasm Child: >3 yr: As modified-release hydrate: 12 mg/kg daily increased to 24 mg/kg daily in 2 divided doses after 1 wk. Intravenous Acute severe bronchospasm Child: Loading dose: same as adult dose. Maintenance dose: 6 mth-9 yr: 1 mg/kg/hr and 10-16 yr: 0.8 mg/kg/hr.
Should be taken on an empty stomach. Take on an empty stomach at least 1 hr before or 2 hr after meals.
Asthma, Acute bronchospasm, Chronic bronchitis, Emphysema, COPD
Nausea, vomiting, abdominal pain, diarrhoea, headache, insomnia, dizziness, anxiety, restlessness; tremor, palpitations. Potentially Fatal: Convulsions, cardiac arrhythmias, hypotension and sudden death after too rapid IV injection.
Hypersensitivity.