Abstract
The concentrations of thioridazine and its main metabolites in erythrocytes from 61 thioridazine-treated patients were determined by gas-liquid chromatography. The mean and range of the erythrocyte concentrations, expressed as percentage of the corresponding plasma concentrations, were: thioridazine, 5.1% (2.0–10.6); side-chain sulfoxide, 5.6% (1.6–10.4); side-chain sulfone, 3.3% (1.1–6.8); ring sulfoxide 2.7% (0.8–4.9). The erythrocyte and plasma concentrations were significantly correlated. The erythrocyte/plasma concentration ratios, all the erythrocyte concentrations, but none of the plasma concentrations except ring sulfoxide were significantly positively correlated to the dose of thioridazine. The erythrocyte/plasma concentration ratio was not correlated to age. In vitro experiments indicated no clinically relevant erythrocyte-mediated oxidation of thioridazine.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Axelsson R, M»rtensson E (1978) Relationship between serum concentrations of thioridazine and its main nonconjugated metabolites and the clinical response in thioridazine-treated patients. Curr Ther Res 24:232–242
Axelsson R, M»rtensson E (1983) Clinical effects related to the serum concentrations of thioridazine and its metabolites. In: Gram LF (ed) Clinical pharmacology in psychiatry. London: MacMillan Press Ltd. pp 165–174
Bradley JV (1968) Distribution-free statistical tests. London: Prentice-Hall
Casper R, Garrer DL, Dekirmenjian H, Chang S, Davis JM (1980) Phenothiazine levels in plasma and red blood cells. Arch Gen Psychiatry 37:301–305
M»rtensson E, Nyberg G, Axelsson R (1975) Quantitative determination of thioridazine and nonconjugated thioridazine metabolites in serum and urine of psychiatric patients. Curr Ther Res 18:687–700
Nyberg G, Axelsson R, M»rtensson E (1978) Binding of thioridazine and thioridazine metabolites to serum proteins in psychiatric patients. Eur J Clin Pharmacol 14:341–350
Shartsburd A, Nwokeafor V, Smith RC (1984) Red blood cell and plasma levels of thioridazine and mesoridazine in schizophrenic patients. Psychopharmacology 82:55–61
Traficante LJ, Sakalis G, Siekierski J, Rotrosen J, Gershon S (1979) Rapid in vitro sulfoxidation of chlorpromazine by human blood: inhibition by an endogenous plasma protein factor. Life Sci 24:337–346
Author information
Authors and Affiliations
Additional information
Offprint requests to: E. Märtensson
Rights and permissions
About this article
Cite this article
Svensson, C., Nyberg, G., Axelsson, R. et al. Concentrations of thioridazine and thioridazine metabolites in erythrocytes. Psychopharmacology 89, 291–292 (1986). https://doi.org/10.1007/BF00174361
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00174361