Serum levels of thioridazine in psychiatric patients and healthy volunteers

There was a strong correlation between the dose and the morning or evening concentration of thioridazine in the blood and a positive correlation was also observed between the age of the patient and the serum level in those who received doses of less than 5 mg/kg body weight.

Abstract

The rate of absorption of thioridazine varied greatly in ten healthy volunteers who took 100 mg in the morning after an overnight fast. The peak level in blood was also variable and it was reached 1 1/4 to 4 h after dosing. Maximal concentrations in the blood varied widely from 0.13 µg/ml to 0.52 µg/ml. No relation was found between the weight or sex of the subjects and the pharmacokinetics of the drug. The serum half life of thioridazine in three healthy volunteers was 9, 10 and 10 h respectively. In a group of 22 patients receiving less than 5 mg/kg body weight a day, there was a strong correlation between the dose and the morning or evening concentration of thioridazine in the blood. A positive correlation was also observed between the age of the patient and the serum level in those who received doses of less than 5 mg/kg body weight.