Over 3 months, 13 Caucasian and 16 Asian schizophrenic patients were
sequentially treated with weight-adjusted fixed doses and clinically
determined, variable doses of haloperidol. During the fixed-dose phase,
Asians had a slightly higher mean serum haloperidol concentration and a
significantly higher rating for extrapyramidal symptoms. During the
variable-dose phase, the Asian patients' mean required dose was
significantly lower, resulting in lower serum haloperidol concentrations at
the first emergence of extrapyramidal symptoms and for optimal clinical
response. These results indicate pharmacodynamic differences in therapeutic
response but no significant difference in steady-state serum concentration
between the two groups.Abstract Teaser