Plasma nor1-chlorpromazine concentrations: effects of age, race, and sex.

Plasma nor1-chlorpromazine (nor1-CPZ) and chlorpromazine concentrations were measured by gas chromatography--mass fragmentometry in 15 inpatients receiving stable doses of chlorpromazine. Nor1-CPZ concentrations averaged 20% of chlorpromazine concentrations and were highly correlated with them. Relative concentrations of nor1-CPZ increased with age. Nor1-CPZ concentrations per milligram dose were higher in black than in white patients.