title: Steady-state pharmacokinetics of theophylline in COPD patients treated with dirithromycin.
abstract: Steady-state theophylline pharmacokinetic parameters were studied in a panel of 14 patients with chronic obstructive pulmonary disease (COPD). Pharmacokinetic parameters were evaluated before, during, and after a 10-day regimen of the macrolide antibiotic, dirithromycin. The addition of dirithromycin (500 mg orally once daily at 7:00 AM) to a sustained-release theophylline dosing regimen (every 12 hours) elicited small changes in the steady-state pharmacokinetics of theophylline, which were not statistically significant. Mean steady-state plasma theophylline trough concentrations (Css,min) were invariant before, during, and after dirithromycin treatment. Mean average steady-state plasma theophylline concentrations (Cav) declined by 7% during dirithromycin treatment (NS), and mean peak plasma concentrations (Css,max) declined by 12% (NS). Theophylline clearance (CL/F) also remained relatively unchanged during dirithromycin treatment exhibiting an increase of only 11% (NS). Dirithromycin treatment does not significantly affect the steady-state pharmacokinetics of theophylline, and its use in COPD patients is not likely to modify treatment outcomes with theophylline.
authors.affiliation: Center for Applied Pharmacology, University of Toledo, College of Pharmacy, OH 43606.
authors.forename: K
authors.initials: K
authors.lastname: Bachmann
authors.forename: L
authors.initials: L
authors.lastname: Jauregui
authors.forename: G
authors.initials: G
authors.lastname: Sides
authors.forename: T J
authors.initials: TJ
authors.lastname: Sullivan
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000900:Anti-Bacterial Agents; D003692:Delayed-Action Preparations; D004334:Drug Administration Schedule; D004347:Drug Interactions; D004917:Erythromycin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000188:drug therapy* / Q000378:metabolism; D018942:Macrolides; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D013806:Theophylline / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D000900:Anti-Bacterial Agents; D003692:Delayed-Action Preparations; D018942:Macrolides; C053853:dirithromycin; D004917:Erythromycin; D013806:Theophylline