Pharmacopsychiatry
DOI: 10.1055/s-0043-116855
Original Paper
© Georg Thieme Verlag KG Stuttgart · New York

Prediction Model of Serum Lithium Concentrations

Kazunari Yoshida1, Hiroyuki Uchida1, 2, Takefumi Suzuki1, 3, Masahiro Watanabe4, Nariyasu Yoshino5, Hitoshi Houchi6, Masaru Mimura1, Noriyasu Fukuoka5
  • 1Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
  • 2Geriatric Psychiatry Division, Centre for Addiction and Mental Health, Toronto, ON, Canada
  • 3Department of Psychiatry, Inokashira Hospital, Tokyo, Japan
  • 4School of Pharmacy, Syujitsu University, Okayama, Japan
  • 5School of Pharmacy, Nihon University, Chiba, Japan
  • 6Department of Pharmacy, Kagawa University Hospital, Kagawa, Japan
Further Information

Publication History

received 16 March 2017
revised 30 June 2017

accepted 13 July 2017

Publication Date:
02 August 2017 (eFirst)

Abstract

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.