title: Comparative steady-state bioavailability of Theo-24 and Theo-Dur in healthy men.
abstract: This study was designed to compare the steady-state theophylline serum concentrations produced by 800 mg daily doses of Theo-24 and Theo-Dur in normal, healthy men administered according to each product's recommended dosing instructions. Sixteen subjects with theophylline clearances ranging from 0.39 to 0.95 mL/min/kg (average, 0.60 mL/min/kg) and theophylline elimination half-lives ranging from 5.1 to 10.5 hours (average 7.9 hours) completed the study. They were all nonsmokers, who ranged in age from 18 to 44 years and were within 10% of normal weight for their height and build. Theo-24 demonstrated a high extent of absorption (89%, range 54% to 115%) relative to Theo-Dur. Both formulations demonstrated similar times to maximum theophylline concentration (11.3 hours for Theo-24 and 11.5 hours for Theo-Dur), similar peak to trough concentration ratios relative to the trough concentration (74% for Theo-24, 62% for Theo-Dur) and similar periods of time within 5 to 15 mg/L (25.2 to 75.7 mumol/L; 21.4 hours for Theo-24, 19.4 hours for Theo-Dur). No "dose dumping" was demonstrated. The results indicate that Theo-24 dosed at least one hour prior to a high-fat breakfast produces serum theophylline concentrations in a range similar to Theo-Dur administered every 12 hours.
authors.affiliation: International Medical Technical Consultants, Inc., Lenexa, Kansas.
authors.forename: R J
authors.initials: RJ
authors.lastname: Dockhorn
authors.forename: E A
authors.initials: EA
authors.lastname: Cefali
authors.forename: A B
authors.initials: AB
authors.lastname: Straughn
mesh_terms: D000293:Adolescent; D000328:Adult; D001682:Biological Availability; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008297:Male; D013806:Theophylline / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D013997:Time Factors
chemical_list: D013806:Theophylline