[24-hour lung function in asthmatic patients: chrono-optimal theophylline therapy as once-daily Euphylong...

In this study we examined the efficacy and pharmacokinetics of a new chrono-optimized theophylline sustained release preparation for once-daily dosing in the evening for treating bronchial asthma. In a randomized, open crossover study, Euphylong (administered once daily at 2000 hours) was compared with the same dose of a reference preparation (subdivided into two equal doses taken at 800 and 2000 hours). Administration and dosage were in accordance with prior determination of clearance. The patients were outpatients during the first six days of every phase, whereas for the following 24-hour measurement period they were admitted as inpatients for measuring the requisite pharmacokinetic and pharmacodynamic data (PEF, FEV1, PEF 25 = 75, FVC). The theophylline levels remained practically constant for 24 hours under conventional theophylline treatment with twice-daily administration. In contrast, the variations of the theophylline serum levels and the night levels were higher after once-daily dosage of Euphylong, and the daytime levels and especially at the end of the dosage interval were lower. Compared with the standard profile without medication, both sustained release preparations improved the airway obstruction significantly and comparably during a 24-hour period. However, in the early morning hours between 200 and 600 both PEF and FEV1 were significantly higher under Euphylong. Between the improvement of PEF and FEV1 and the theophylline serum concentrations there was a significant correlation between 200 and 600 under Euphylong only. It is concluded that the treatment of asthma with the chrono-optimized once-daily theophylline preparation Euphylong over night is more effective than treatment with a conventional preparation in twice-daily dosage.