Single-dose slow-release aminophylline at night prevents nocturnal asthma

Twelve asthmatic patients with nocturnal wheezing were given a single nocturnal oral dose of slow-release aminophylline or matched placebo in a double-blind crossover trial. A dose of slow-release aminophylline (mean 683 mg; 10.4 mg/kg) gave a therapeutic plasma-theophylline concentration 10 h later (mean 10.9 mg/l). This was not associated with any adverse effects. Mean peak expiratory flow on waking was significantly greater with aminophylline (332 +/- 31 l/min) than placebo (283 +/- 32 l/min), whereas evening values did not differ. There was a significant difference between morning and evening peak flow on placebo (mean 22%) but not on aminophylline (5%), indicating abolition of the morning fall in peak flow. This was not at the expense of response to beta-agonists, since the response to inhaled salbutamol was the same for both treatments. The use of extra metered doses of inhaled beta-agonist during the night was significantly less with aminophylline, and there was a subjective improvement in nocturnal symptoms in all patients. Slow-release aminophylline in adequate dosage appears to be the most effective treatment yet demonstrated for nocturnal asthma.