Comparison of morning versus evening dosing with a new once-daily oral theophylline formulation.

A double-blind, cross-over comparison of morning (8 A.M.) versus evening (10 P.M.) dosing regimens with a new once-daily oral theophylline (Uniphyl, Purdue Frederick) was performed. The comparison was based upon steady-state theophylline pharmacokinetics, spirometric measurements over 24 hours, the patients' quantitative reporting of asthmatic symptoms, and medication side effects. No statistically significant differences were observed in any theophylline parameter between the dosing regimens. Evening dosing, but not morning dosing, resulted in a significant attenuation of the early morning dip in pulmonary function. The morning severity of wheezing, chest tightness, and shortness of breath was significantly reduced after evening dosing. Overall no difference in the incidence of symptoms was noted. No significant differences in side effects were noted. Evening dosing with Uniphyl produced a significant improvement in morning pulmonary function, and this benefit was subjectively noted by the patients. No decline in this benefit was noted later in the day. Evening dosing with Uniphyl clearly is superior to morning dosing.