[Chronotherapy of bronchial asthma: circadian rhythms in peak expiratory flow. The report II: Circadian rhythms of peak expiratory flow in asthmatic patients and effect of sustained-release theophylline on various types of the circadian rhythms].

We monitored peak expiratory flow (PEF) in outpatients with adult bronchial asthma in 17 sites in Chiba prefecture 4 times daily for 2 weeks, using a peak flow meter to categorize the patients by circadian patterns of PEF. Then a sustained-release theophylline preparation formulated for once-daily dosing was administered to these patients grouped to examine the effect of the drug on circadian rhythms in PEF. Analysis was performed in 215 of total 245 patients enrolled as a result of excluding 30 ineligible patients. 187 patients (87.0%) exhibited a certain rhythm in their PEF, and 28 patients (13.0%) did not show any particular rhythm. These 187 patients with a certain rhythm in PEF were grouped into 63 patients (29.3%) of morning-dip type, 83 patients (38.6%) of peak type, 7 patients (3.3%) of evening-dip type, and 34 patients (15.8%) of flat type. And there were no trough-type patients. Uniphyl tablets were administered once a day at a daily dosage of 400 mg after supper to 124 patients of the above 187 patients grouped according to circadian patterns of PEF. Uniphyl was particularly effective in the morning-dip type and the peak type. This result suggests that it is necessary to take circadian rhythms of PEF into consideration in drug therapy for patients with bronchial asthma.