Abstract
The binding of phenobarbital and secobarbital by polyvinylpyrrolidone (PVP) was studied by equilibrium dialysis and ultrafiltration techniques. Significant quantities of both barbiturates were bound at concentrations of PVP comparable to those which were attained in the serum and urine by dosing rabbits with 2 g/kg per hour of PVP of molecular weight 10 000 (PVP-10). Treatment of rabbits intoxicated with phenobarbital and secobarbital with PVP-10 enhanced the renal clearance of the barbiturates and ameliorated the toxic state more rapidly than did treatment with dextran of the same molecular weight. This effect was probably due to binding by PVP of a portion of the barbiturate in a non-reabsorbable form in tubular urine as well as binding of the barbiturate in a nondiffusible form in the extracellular space.