• The purpose of this investigation was to determine the relationship between serum levels of the neuroleptic agent thiothixene and tardive dyskinesia in schizophrenics of a wide age range. Forty-one male schizophrenic subjects, 21 with tardive dyskinesia and 20 without, were given a fixed dosage of thiothixene hydrochloride (10 mg orally four times daily) after a drug-free period of one week. Higher steady-state serum levels of thiothixene (obtained after five days of a fixed-dosage schedule) were associated with greater degrees of tardive dyskinesia. This relationship was independent of the relationship between tardive dyskinesia and age.
Yesavage JA, Tanke ED, Sheikh JI. Tardive Dyskinesia and Steady-State Serum Levels of Thiothixene. Arch Gen Psychiatry. 1987;44(10):913-915. doi:10.1001/archpsyc.1987.01800220085012