Thiothixene , dosing

Limited evidence indicates that carbamazepine plus an antipsychotic may also benefit some schizophrenic patients. This is an interesting possibility in view of the similar antimanic properties of lithium and carbamazepine (375). This area requires further research, especially to clarify the indications for combining anticonvulsants with an antipsychotic. For example, mania complicated by psychotic features may benefit from lithium, valproate, or carbamazepine augmented by antipsychotics. Because carbamazepine induces the metabolism of at least some antipsychotics (e.g., haloperidol, thiothixene), dose adjustment based on TDM may be necessary to achieve the optimal effect. 

Thiothixene (Navane). Thiothixene is sometimes grouped with the medium potency and at other times with the high potency antipsychotics. Its potency is actually about halfway between these two groups. Thiothixene is available in both oral and injectable forms. It should be initiated at doses of about 5mg/day and can be... 

Trifluoperazine (Stelazine). Trifluoperazine is very similar to thiothixene. It comes in both oral and injectable forms. Its dose range is the same as thiothixene. 

Yesavage et al. (305) treated 48 acute schizophrenics with thiothixene (80 mg/day), measuring serum and red blood cell (RBC) concentrations 2 hours after the morning dose. Serum levels ranged from 3 to 45 ng/mL, with a linear relation between clinical response during the first week of treatment and serum (r = 0.5), as well as RBC levels (r = 0.64). By contrast, Mavroidis et al. ( 287) found a curvilinear relationship between thiothixene plasma levels and clinical response. Thus, levels ranging between 2.0 and 15 ng/mL, measured 10-12 hours after the last dose, were associated with clinical improvement. 

In one single-blind study, 17 schizotypal patients were given a modest dose of halopehdol (i.e., 2 to 12 mg per day), which produced some benefit, although many were sensitive to the adverse effects of this drug (216). The study by Goldberg et al. (217) also found that thiothixene benefited both schizotypal disorder and borderline personality disorder (BPD). Similarly, low-dose antipsychotics had a modest effect in patients with both schizotypal and obsessive-compulsive personality disorders (218). 

Goldberg SC, Schulz SC, Schulz PM, et al. Borderline and schizotypal personality disorders treated with low-dose thiothixene vs placebo. Arch Gen Psychiatry 1986 43 680-686. 

Serban G, Seigel S. Responses of borderline and schizotypal patients to small doses of thiothixene and haloperidol. Am J Psychiatry 1984 141 1455-1458. 

These anguished responses were rapid in onset. Van Putten et al. (1980) also described frequent severe dysphoric reactions to single doses of chlorpromazine and thiothixene. 

When thiothixene is dosed too high, it can induce or worsen negative symptoms of... 

Huang CC, Gerhardstein RP, Kim DY, Hoiiister L. Treatment-resistant schizophrenia controiied study of moderate- and high-dose thiothixene, int Ciin Psychopharmacoi f 987 2 69-75. 

Thioxanthenes are used in the treatment of psychosis, including schizophrenia, senile psychosis, pathological jealousy, and borderline personality disorder. Other uses include the treatment of pain, postoperative neuralgia, sedation, anxiety neurosis, childhood behavior problems, and depression. The maximum therapeutic daily oral dose for chlorprothixene, flupenthixol, and thiothixene is 600, 224, and 60 mg respectively the maximum intramuscular dose of each is 200 mg day 100 mg weekly, and 30 mg dayrespectively. Some thioxanthenes and thioxanthenones have shown signs in mice and in vitro assays of possible human therapeutic potential against tumors, and some thioxanthenes have been shown to have cytotoxic and antimicrobial activities. 

The neuroleptic (at first called tranquillizing ) action of these pheno-thiazines was later found in other chemical series, notably among the thioxan-thenes [e.g. chlorprothixene 12.111)]. and butyrophenones [e.g. haloperidol 12.112)]. At first, the dose of the butyrophenones was much lower than was needed for the other two categories, but now these too have low-dose examples such as perphenazine, trifluoperazine, fluphenazine, and thiothixene. ... 

The psycholeptic action, characteristic of these phenothiazines, was later found in other series, notably among the thioxanthenes [e.g. chlor-prothixine (75.74), Taractan ], and the phenylbutyrophenones introduced by Janssen in Belgium about 1958 [e.g. haloperidol (75.75)]. To-day a distinction is made between the high-dose psycholeptics, such as chloro-promazine and chlorprothixen, which have an additional sedative effect, and the low-dose psycholeptics, such as perphenazine, trifluoperazine, fluphenazine, haloperidol, and thiothixene, which have a strong, but purely psycholeptic, action. 

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