TITLE:
Pharmacokinetics of Lithium in Egyptian Bipolar Patients: Dosage Adjustment Approach
AUTHORS:
Abdel-Hameed Ibrahim Mohamed Ebid, Dina Awny Tawfik Abd-Allah, Mahmoud Mamdouh Mohamed Elhabiby
KEYWORDS:
Lithium; Pharmacokinetics; Bipolar Disorder
JOURNAL NAME:
Pharmacology & Pharmacy,
Vol.5 No.4,
April
23,
2014
ABSTRACT: Due to its proven clinical effectiveness, lithium has been considered as
a corner stone for the long-term treatment of Bipolar Disorder (BPD) for more
than half a century. The objective of this study was to evaluate the effect of
patients’ different co-variables on lithium pharmacokinetics and the
development of a pharmacokinetic model for the estimation of lithium clearance
in Egyptian bipolar patients; this model can be used afterwards during dosage
adjustment to achieve target’s steady-state plasma concentrations in similar
settings. The study was conducted on 65 adult Egyptian bipolar patients of both
genders, in both the in- and out-patient settings in the Institute of Psychiatry,
Faculty of Medicine, Ain Shams University, Cairo, Egypt. Patients’ full
profiles were prepared, containing all their data. Single daily dose regimen
was followed by all patients and one blood sample was drawn 12 ± 0.5 hours post dose for steady-state lithium
concentration, sodium level and serum creatinine determinations. Lithium trough
levels were determined using Flame Emission Photometry technique. Data
analysis and regression modeling revealed a significant correlation between
total body weight (TBW), body surface area (BSA) and lithium clearance. Due to
multicollinearity, BSA was excluded from the basic non-linear regression
equation and TBW was found to be the only covariate affecting lithium
clearance. Mean lithium clearance was found to be 0.243 ± 0.097 Lit/Kg/day, ranging from 0.091 to 0.71
Lit/Kg/day.