Why are free serum concentrations recommended for monitoring of phenytoin and valproic acid in patients with renal failure?
Uremia. Both phenytoin and valproic acid are highly bound to serum albumin and are displaced from protein binding sites in the presence of uremia.
Contributor: Rachel Schult, PharmD, DABAT, University of Rochester Medical Center
Keller F, et al. Pharmacokinetic effects of altered plasma protein binding of drugs in renal disease. Eur J Drug Metab Pharmacokinet 1984;9(3):275-82. doi: 10.1007/BF03189651.
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