Some pharmacokinetic characteristics of furafylline, a new 1,3,8-trisubstituted xanthine

After administration of furafylline, a, 1,3,8-trisubstituted xanthine, to beagle dogs at 0.5 and 10 mg kg-1 an elimination half-life 2-10 times longer than that of theophylline was observed. The kinetics were dose-dependent but no phase I metabolites were detected. When the compound was given orally to humans at a dose of 1.3-1.9 mg kg-1 a mean beta elimination half-life of 48.1 +/- 10.8 h was obtained after an initial distribution phase. Evidence of non-linear kinetics for plasma levels below 0.6 microgram ml-1 was also obtained. Other 1,3,8-trisubstituted xanthines, may also have a lower elimination rate than theophylline.