ISSN:
1432-1041
Keywords:
phenytoin
;
dialysis encephalopathy
;
protein binding
;
continuous ultrafiltration
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Medicine
Notes:
Summary Protein binding of phenytoin was assessed in one patient with dialysis encephalopathy before and after haemodialysis. Phenytoin concentrations were measured by radioimmunoassay and continuous ultrafiltration was used to assess phenytoin binding. At a serum concentration of 60 µmol.1−1 the percentage of phenytoin bound to serum albumin was considerably lower in the patient serum (79.95% predialysis; 92.09% postdialysis) than that in three normal sera (97.90±0.17%). Analysis of Scatchard plots indicated two classes of binding sites. In class I both the affinity and capacity for binding phenytoin were reduced in the pre and post-dialysis serum, whereas in class II the capacity of the uraemic serum was increased although the intrinsic association constant was greatly reduced. It was concluded that in vivo haemodialysis is associated with large fluctuations in the protein binding of phenytoin, in which the concentration of endogenous dialysible metabolites are strongly implicated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00563560
