Controlled trial of slow-release aminophylline in childhood asthma: are short-term trials valid?
Slow-release aminophylline, although widely used for the prophylaxis of childhood asthma, has had only limited formal assessment. A four-month double-blind cross-over trial of slow-release aminophylline (14 mg/kg twice daily) was carried out in 24 children with perennial asthma. Satisfactory serum theophylline concentrations were obtained in 17 children, with few side effects. There was a significant improvement in mild daytime and night-time symptoms. The incidence of more severe symptoms was unaffected. Treatment did not improve the mean peak expiratory flow or reduce the incidence of use of bronchodilators. It is concluded that slow-release aminophylline has a place in the prophylaxis of perennial childhood asthma but is unsuitable for children who suffer from severe attacks. The cross-over trial design has severe limitations.