A comparative trial of the clinical efficacy and pharmacokinetics of 12-hour and 24-hour controlled release theophylline preparations in patients with chronic asthma.

A double-blind crossover comparison of a 12-hour theophylline preparation (Theo-Dur) and a 24-hour theophylline preparation (Theo-24) was conducted with 20 young adult chronic asthmatic patients requiring daily bronchodilator therapy. The study group included 11 males and nine females ranging in age from 12 to 28 years. Clinical status and serum theophylline levels were monitored during the 4-week dosing interval on each medication. On the last day of each test period subjects were monitored closely throughout a 24-hour period. The results indicated little clinical difference between the two medications although there were statistically significant differences in the pharmacokinetic behavior between the two theophylline preparations.