SINGLE-DOSE PHARMACOKINETIC STUDY OF LITHIUM IN TAIWANESE CHINESE BIPOLAR PATIENTS/

Objective: The purpose of this study is to investigate the single dose pharmacokinetics of lithium in Taiwanese/Chinese bipolar patients for future interracial comparisons. Method: Eight bipolar patients took 9 00 mg of lithium carbonate after overnight fasting. Blood samples of 5 mL were taken after 15 min, 30 min, 45 min, 1 h, 2 h, 3 h, 4 h, 7 h, 9 h, 15 h, 25 h and 31 h after dosing. The computer programs CSTRIP an d PCNONLIN were used for pharmacokinetic analysis. Results: The pharma cokinetic parameters obtained were as follows: C-max, 0.970 +/- 0.170 (SD) mmol/L; T-max, 1.59 +/- 0.78 h; AUC(31 h) = 548.9 +/- 135.4 mmol. m/l; AUC(infinity) = 722.6 +/- 262.7 mmol.m/l; beta-half-life = 16.3 /- 7.18 h; K-half-life = 0.613 +/- 0.442 h; Cl-oral = 1.13 +/- 0.39 ml /min/kg; Vd/F = 1.43 +/- 0.387 L/kg. Most of the pharmacokinetic param eters were within the ranges reported in investigations of Caucasian s ubjects. Conclusions: This study showed that racial differences in lit hium pharmacokinetics might not exist. We suggest that methodological designs, including method of blood sampling, measurement of lithium, a nd pharmacokinetic and statistical calculations, be standardised if fu ture cross-ethnic comparisons are to be conducted.