For example, if dyspnea while climbing stairs was identified, the question read “How short of breath were you today when you were climbing stairs?,” with response options of 1 (extremely short of breath), 2 (very short of breath), 3 (quite a bit short of breath), 4 (moderately short of breath), 5 (mildly short of breath), 6 (a little short of breath), and 7 (not at all short of breath). Sustained-release theophylline and an identical placebo were dispensed in pairs of 10-day periods (ie, 10 days for theophylline and then 10 days for placebo). The order of theophylline and placebo within pairs was randomly determined by a computergenerated scheme held in pharmacies at each site; the physicians supervising the n of 1 trials were also unaware of which drug the patient was taking. For patients receiving theophylline prior to randomization (all no-prior-theophylline-use patients and all prior-theophylline-use patients taking theophylline at the time of recruitment), the starting dose of theophylline was the same as that used before randomization. For prior-theophylline-use patients who were receiving a preparation containing oxtriphylline or aminophylline, the starting dose of theophylline was adjusted accordingly website canadian family pharmacy online.
Diaries were completed on days 6 to 10, inclusive, for each treatment period to allow for drug washout from days 1 to 5. Patients could contact the study physician before completing a treatment period if their symptoms worsened. If the change could not be explained clinically by an event other than the withholding of theophylline (eg, a respiratory infection), patients switched to the other treatment. Patients were reviewed by the physician at the end of each treatment pair. A maximum of four pairs could occur. However, the patient or physician could stop the n of 1 trial earlier for any reason.