Thioridazine blood levels in patients receiving different oral forms

Patients taking regular sugar‐coated tablets, a liquid concentrate, and a “sustained‐release” preparation of thioridazine showed little difference in serum levels of the drug. Typical cumulation of drug in serum took place within the first 3 to 4 days, followed by a maintained drug level. Only a slight difference in the average level of the drug could be observed during day or night with all forms of their medication and whether given once daily or in divided doses. While serum levels varied with individuals, in each there was little fluctuation from the mean average level. Substantially equal drug levels, regardless of dosage schedules or medication form, pOint to the cumulation of thioridazine.