Improved control of asthma in the office setting. A large-scale study of once-daily evening doses of theophylline.

A large-scale, multi-investigator open evaluation compared a once-daily regimen of controlled-release theophylline (Uniphyl tablets) with previous twice- or thrice-daily methylxanthine regimens. Three hundred asthmatic patients, 78 percent prone to nocturnal episodes during prior therapy, completed the investigation. Eighty-two percent of the patients were treated for moderate or severe disease. After a one-week evaluation of baseline theophylline therapy (with adjunctive medication), the patients substituted evening doses of the once-daily drug in approximate milligram-for-milligram equivalent doses. Concomitant medications were allowed as before. Nighttime and morning asthma control improved significantly without deterioration in the evening, and without increased side effects. Once-daily therapy resulted in markedly fewer night awakenings involving inhaler use (p less than 0.01), and near 60 percent reductions in the number of patients with nighttime or early morning exacerbations (p less than 0.01). Control of morning chest tightness, wheeze, and dyspnea improved significantly (p less than 0.01), and patients' as well as investigators' global evaluations favored once-daily treatment (p less than 0.01). Morning peak expiratory flow rates improved both at home (p less than 0.01) and at the office (p = 0.05). The forced expiratory volume in one second at the office increased modestly in the entire group. It is concluded that Uniphyl is effective and well tolerated when administered in once-daily evening doses.