Assessing the efficacy and safety of q. d. theophylline therapy: a multicenter study

One hundred thirty-two asthmatic patients with bronchial asthma were studied by 20 independent investigators during this 49-day study. One hundred sixty-four patients entered into this study, and up to 132 were judged evaluable for statistical purposes. Criteria for entry included current q 12-hour therapy with an available theophylline product (eg, Theo-Dur, Slo-Bid, etc). Use of beta-agonist aerosols PRN was permitted, as was use of steroid aerosols for short periods of time. Chronic treatment with oral corticosteroids or other oral bronchodilators was prohibited. Baseline peak and trough serum theophylline concentrations (STCs) and performance of pulmonary function tests (PFTs) were determined during q 12-hour treatment. Patients were then switched within one dosing interval to an equivalent single daily dose of Theo-24 and maintained on this therapy for the duration of the study. STC and PFT measurements were repeated on days 8, 21, and 49 of the Theo-24 study period. Throughout the 49-day study, patients measured their peak expiratory flow rate at home, at 8 AM, and at 8 PM using a Mini-Wright Peak Flow Meter. These data, along with asthma symptomatology and frequency of inhaled bronchodilator aerosol usage, were recorded daily in diary form. Three days after the start of Theo-24 treatment, the mean peak STC (11.18 micrograms/mL) was not significantly different from the mean peak STC with q 12-hour treatment (11.4 micrograms/mL) in 121 patients.(ABSTRACT TRUNCATED AT 250 WORDS)