title: Setting confidence intervals for drug concentrations from pharmacokinetic parameters.
abstract: OBJECTIVE
  To describe and illustrate a convenient method of forecasting drug concentrations with confidence intervals (CIs) using the means and standard deviations of relevant pharmacokinetic parameters (e.g., clearance and volume of distribution).
  
  
  METHODS
  Using summary statistics from previously published reports, a Monte Carlo technique employing a SAS random number generator creates an arbitrarily large "sample" of each pharmacokinetic parameter. A related "sample" of drug concentrations is provided by inserting the parameters into the appropriate model. A point estimate of the mean drug concentration with a CI is calculated using standard statistical methods. Both the one- and two-compartment body models are illustrated using previous investigations of gentamicin and lidocaine, respectively.
  
  
  RESULTS
  One-compartment simulations describe CIs for gentamicin concentrations that vary widely depending on the source of the clearance and volume of distribution parameters. Lidocaine CIs using a two-compartment analysis indicate a range of concentrations quite different from the expected mean.
  
  
  CONCLUSIONS
  CIs provide a perspective of drug therapy that is considerably more informative than a simple point estimate of the mean concentration.
authors.affiliation: Department of Pharmacy Services, University of California, Davis Medical Center, Sacramento.
authors.forename: J F
authors.initials: JF
authors.lastname: Inciardi
authors.forename: N H
authors.initials: NH
authors.lastname: Willits
mesh_terms: D016001:Confidence Intervals; D004358:Drug Therapy; D005544:Forecasting; D005839:Gentamicins / Q000493:pharmacokinetics; D006801:Humans; D008012:Lidocaine / Q000493:pharmacokinetics; D008954:Models, Biological; D010599:Pharmacokinetics
chemical_list: D005839:Gentamicins; D008012:Lidocaine