Kinetics of intravenous and oral pentoxifylline in healthy subjects

Abstract

The kinetics of a sustained-release formulation of pentoxifylline were compared with those of a capsule and an i.v. infusion. Ten healthy subjects received each of the oral pentoxifylline formulations (400 mg) 3 times/day for 9 days in a random crossover fashion. Pentoxifylline (200 mg) was also given i.v. on a separate day. After i.v. pentoxifylline, plasma levels declined in a biphasic manner, with a terminal t1/2 [half-time] of 1.63 .+-. 0.8 h. Plasma clearance was 1333 .+-. 481 ml/min and the volume of distribution was 168 .+-. 82.3 l. Cumulation of pentoxifylline in plasma after repeated dosing was minimal. Plasma levels of the active 5-hydroxylated metabolite were generally higher than those of the parent drug after both routes of administration. Urinary excretion of 2 acid metabolites after oral and i.v. dosing indicated almost complete absorption of drug-related substances from both oral formulations, although bioavailability averaged 20-30%.