Dose-dependency of theophylline clearance and protein binding.

Dose-dependency of theophylline clearance and protein binding.

Dose-dependency in theophylline pharmacokinetics and protein binding characteristics was examined in 10 healthy male volunteers. Theophylline disposition was determined after an intravenous infusion of both 1 mg/kg and 6 mg/kg aminophylline in a randomised crossover study. There was considerable intrasubject variability in theophylline clearance but no significant dose-dependency. Theophylline ...

Protein binding of theophylline.

Influence of chronic dosing on theophylline clearance.

Theophylline clearance was studied in normal healthy volunteers before and after chronic oral dosing. Oral theophylline clearance showed a significant decrease (P less than 0.001) from 59.3 +/- 6.48 ml/min (mean +/- s.e. mean, n = 10) to 48.0 +/- 6.4 ml/min. Steady-state intravenous clearance decreased by 26 +/- 2% from 55.1 +/- 7.7 ml/min to 41.0 +/- 5.96 ml/min (mean +/- s.e. mean, n = 6; P l...

Inhibition of theophylline clearance by coadministered ofloxacin without alteration of theophylline effects.

The influence of multiple doses of ofloxacin (ORF 18489) on the disposition of theophylline was studied in 15 male volunteers. Subjects were confined in the Clinical Research Unit for 13 days and given a xanthine-free diet. A single dose (3 mg/kg) of theophylline was given orally, and blood samples were collected at fixed time intervals for 36 h. The concentrations of theophylline were measured...

CYP1A2 polymorphism and theophylline clearance in Korean non-smoking asthmatics

BACKGROUND Theophylline is mainly metabolized by cytochrome P450 (CYP) 1A2 and CYP2E1 which show inter-individual variations. However, the underlying mechanism remains unknown in humans. We investigated the relationship between differences in theophylline clearance and genetic polymorphisms in the CYP1A2 and CYP2E1 gene in 89 Korean asthmatic patients. METHODS Polymerase chain reaction (PCR) ...