title: Comparative pharmacokinetics of theophylline and dyphylline following intravenous injection in rabbits.
abstract: The pharmacokinetics of theophylline and dyphylline in four rabbits were investigated following intravenous injection. Each rabbit received theophylline (10 mg/kg) first then dyphylline (25 mg/kg) two weeks afterwards as an intravenous bolus injection. The serum concentration-time data for both theophylline and dyphylline were best fitted to the two compartment open model. The half-lives of theophylline and dyphylline were 5.5 +/- 1.3 and 0.74 +/- 0.10 hr, respectively. The apparent volume of distribution (Vdbeta) and total body clearance (TBC) of dyphylline (Vdbeta = 1008 +/- 156 ml/kg; TBC = 942 +/- 118 ML/HR/KG)a = 1008 +/- 156 ml/kg; TBC = 942 +/- 118 ml/hr/kg) were much higher than those of theophylline (Vdbeta = 545 +/- 160 ml/kg; TBC = 69 +/- 10 ml/hr/kg). Thus both theophylline and dyphylline showed pronounced difference in their pharmacokinetic profile.
mesh_terms: D000818:Animals; D004400:Dyphylline / Q000008:administration & dosage / Q000378:metabolism*; D005260:Female; D007275:Injections, Intravenous; D007700:Kinetics; D008297:Male; D011817:Rabbits; D013806:Theophylline / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000378:metabolism*
chemical_list: D004400:Dyphylline; D013806:Theophylline