title: Simultaneous tubular excretion and reabsorption of pindolol in man.
abstract: The plasma concentrations of pindolol have been examined following the administration of single doses of 15 mg tablets to eight healthy male subjects. The apparent half-life of elimination in plasma (t1/2 = 4.05 h) and in urine (t1/2 = 3.21 h) was calculated using conventional pharmacokinetic methods. The renal clearance was estimated by plotting urinary excretion rates versus plasma concentrations; for all subjects these plots were curved. In addition to these graphical estimations, the plasma concentrations of pindolol and the urinary excretion data for each volunteer were simultaneously fitted using a one or two-compartment open body model; a computer program using non-linear regression algorithms was used. This procedure did not give an adequate fit to the data. Another type of data analysis, using a population - based model, permitted us to show that the renal elimination of pindolol in man comprises of two separate processes - tubular secretion and reabsorption, which was partially saturable under the experimental conditions. The theoretical relevance and clinical significance of these findings are discussed.
mesh_terms: D000042:Absorption; D000328:Adult; D006207:Half-Life; D006801:Humans; D007684:Kidney Tubules / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D008657:Metabolic Clearance Rate; D008954:Models, Biological; D010869:Pindolol / Q000378:metabolism*
chemical_list: D010869:Pindolol