Once-daily theophylline in the treatment of nocturnal asthma
The efficacy and side-effects of individually adjusted doses of controlled-release theophylline given once daily in the evening (average dose 650 mg) were compared with those of standard treatment with controlled-release terbutaline 7.5 mg b.d. Thirty-six asthmatics with regular morning obstruction (“morning dipping”) were studied over two treatment periods each of two weeks, according to a crossover, randomized, double blind design. Morning peak expiratory flow (PEF) was slightly but significantly higher with theophylline (363 l·min−1) than terbutaline (342 l·min−1). Feelings of dyspnoea on waking in the morning were also less pronounced with theophylline. There were no other differences between the treatment periods during the day or night, with respect to dyspnoea or any the other symptoms. Side-effects were mild and were reported with similar frequencies during both treatments. It is concluded than an individually adjusted dose of once-daily theophylline administered in the evening is at least as effective as conventional therapy with controlled-release terbutaline in preventing nocturnal and early morning asthma, when both drugs are added to regular medication with inhaled sympathomimetics and steroids.