Phenytoin Total Drug Level (Adjusted for Hypoalbuminemia and Renal Function)

Phenytoin Measured
Renal Fx Adequate Renal Function (0.2)

Creat Clearance < 10 mL/min (0.1)
Serum Albumin
Phenytoin Adjusted
Decimal Precision:
PhenytoinAdjusted = PhenytoinMeasured /((SerumAlbumin * RenalFx ) + 0.1)
  • Equation parameters such as Renal Fx have two or more discrete values that may be used in the calculation. The numbers in the parentheses, e.g. (0.2), represent the values that will be used.
  • This calculator is used to predict the total phenytoin level (adjusted for hypoalbuminemia and renal function) that is commonly used for phenytoin dosage adjustment.
  • To predict the unbound, free phenytoin level in patients with hypoalbuminemia, please see the calculator Phenytoin Free (Unbound) Drug Level (Adjusted for Hypoalbuminemia.)
  1. Martin E, Tozer TN, Sheiner LB, Riegelman S. The clinical pharmacokinetics of phenytoin. J Pharmacokinet Biopharm. 1977 Dec;5(6):579-96.
  2. Dasgupta A, Dennen DA, Dean R, McLawhon RW. Prediction of free phenytoin levels based on [total phenytoin]/[albumin] ratios. Potential errors with hypoalbuminemia. Am J Clin Pathol. 1991 Feb;95(2):253-6.
Legal Notices and Disclaimer
All information contained in and produced by the MedCalc 3000 system is provided for educational purposes only. This information should not be used for the diagnosis or treatment of any health problem or disease. THIS INFORMATION IS NOT INTENDED TO REPLACE CLINICAL JUDGMENT OR GUIDE INDIVIDUAL PATIENT CARE IN ANY MANNER. Click here for full notice and disclaimer.
MedCalc 3000 is Copyright © 1998-2011 Foundation Internet Services, LLC    [Build 244179 v11.2.2]