title: Clinical utility of a Bayesian dosing program for phenytoin.
abstract: We performed two studies to assess the clinical utility of a Bayesian regression analysis computer program for phenytoin (PHT). In a randomized prospective study of 40 epileptic patients, the dosing program was significantly more accurate (p = 0.002) and less biased (p = 0.02) than a group of physicians at hitting a target PHT serum-concentration. Initial serum PHT concentrations that were not steady state were associated with the largest dosing errors by physicians but did not affect the accuracy of the dosing program. In a second study, we used the dosing program to predict 91 serum concentrations in 31 patients with PHT toxicity after the drug was stopped (initial concentration 26-69 micrograms/ml). The program predicted serum concentrations with a mean error of 3.49 +/- 0.29 micrograms/ml without significant tendency to over- or underpredict. We conclude that this dosing program may aid clinicians by improving dosing accuracy and predicting serum concentrations in patients with PHT toxicity.
authors.affiliation: Department of Neurology, Veterans Administration Medical Center, Dallas, Texas.
authors.forename: M D
authors.initials: MD
authors.lastname: Privitera
authors.forename: R W
authors.initials: RW
authors.lastname: Homan
authors.forename: T M
authors.initials: TM
authors.lastname: Ludden
authors.forename: C C
authors.initials: CC
authors.lastname: Peck
authors.forename: M R
authors.initials: MR
authors.lastname: Vasko
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001499:Bayes Theorem; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010672:Phenytoin / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics*; D011336:Probability; D012984:Software
chemical_list: D010672:Phenytoin