Prediction Model of Serum Lithium Concentrations

Pharmacopsychiatry. 2018 May;51(3):82-88. doi: 10.1055/s-0043-116855. Epub 2017 Aug 2.


Introduction: Therapeutic drug monitoring is necessary for lithium, but clinical application of several prediction strategies is still limited because of insufficient predictive accuracy. We herein proposed a suitable model, using creatinine clearance (CLcr)-based lithium clearance (Li-CL).

Methods: Patients receiving lithium provided the following information: serum lithium and creatinine concentrations, time of blood draw, dosing regimen, concomitant medications, and demographics. Li-CL was calculated as a daily dose per trough concentration for each subject, and the mean of Li-CL/CLcr was used to estimate Li-CL for another 30 subjects. Serum lithium concentrations at the time of sampling were estimated by 1-compartment model with Li-CL, fixed distribution volume (0.79 L/kg), and absorption rate (1.5/hour) in the 30 subjects.

Results: One hundred thirty-one samples from 82 subjects (44 men; mean±standard deviation age: 51.4±16.0 years; body weight: 64.6±13.8 kg; serum creatinine: 0.78±0.20 mg/dL; dose of lithium: 680.2±289.1 mg/day) were used to develop the pharmacokinetic model. The mean±standard deviation (95% confidence interval) of absolute error was 0.13±0.09 (0.10-0.16) mEq/L.

Discussion: Serum concentrations of lithium can be predicted from oral dosage with high precision, using our prediction model.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Bipolar Disorder / blood*
  • Bipolar Disorder / drug therapy
  • Creatinine / blood
  • Depression / blood*
  • Depression / drug therapy
  • Dose-Response Relationship, Drug
  • Drug Monitoring
  • Female
  • Humans
  • Lithium / blood*
  • Lithium / therapeutic use
  • Male
  • Middle Aged
  • Models, Biological*
  • Predictive Value of Tests
  • Schizophrenia / blood*
  • Schizophrenia / drug therapy
  • Young Adult


  • Lithium
  • Creatinine