[Euphylong in standard dosage: comparison with an international retard preparation for twice-daily administration in recommended dosage].

24 patients with COPD and delta FEV1 greater than 15% were included in a double-blind crossover study. 7 dropouts due to deterioration of findings and incomplete data reduced the number of assessable patients to 17. Most of the patients had been pretreated with a slightly higher theophylline dosage before initiation of the study. In the preliminary period a 24-hour profile of the peak flow was set up with a morning and evening theophylline level. During the 5-day treatment intervals a 24-hour profile of the serum theophylline levels and of the peak flow was recorded at two-hour intervals. A complete lung function test was performed in each phase. The pharmacokinetic data of both preparations are comparable. Euphylong showed a bioavailability of 83%, the maximum of the serum level was attained at night. Serum level variations were only slightly higher than those of the reference drug. Euphylong had a night level of 24% above the daily average (reference drug 3%). This was associated in a part of the group, about one-third of the total number of patients, with an improvement of the "morning dip" compared with the preliminary period or the reference drug. Over the entire group of patients there were no differences between both drugs or the preliminary period that could be ascribed to the theophylline premedication. An advantage shown by Euphylong was the better predictability of the serum levels. During the time period of the clinical routine the deviation of the serum level from the actual serum maximum was less than 15%.