Thiothixene is metabolized in the liver and is excreted mainly in feces via biliary elimination as unchanged drug and as the demethyl, sulfoxide, demethylated sulfoxide, and hydroxylated thiothixene derivatives.
IDENTIFICATION AND USE: Thiothixene is a solid. It is antipsychotic agent and dopamine antagonist. Thiothixene capsules are effective in the management of schizophrenia. HUMAN STUDIES: Tardive dyskinesia, a syndrome consisting of potentially irreversible, involuntary, dyskinetic movements may develop in patients treated with antipsychotic drugs, including thiothixene. A potentially fatal symptom complex sometimes referred to as Neuroleptic Malignant Syndrome (NMS) has been reported in association with antipsychotic drugs, including thiothixene. Clinical manifestations of NMS are hyperpyrexia, muscle rigidity, altered mental status and evidence of autonomic instability (irregular pulse or blood pressure, tachycardia, diaphoresis, and cardiac dysrhythmias). Manifestations of overdose include muscular twitching, drowsiness and dizziness. Symptoms of gross overdosage may include CNS depression, rigidity, weakness, torticollis, tremor, salivation, dysphagia, hypotension, disturbances of gait, or coma. Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Thiothixene may be additive with or may potentiate the action of other CNS depressants (including alcohol), anticholinergics, or hypotensive agents. ANIMAL STUDIES: In animal reproduction studies with thiothixene, there was some decrease in conception rate and litter size, and an increase in resorption rate in rats and rabbits. After repeated oral administration of thiothixene to rats (5 to 15 mg/kg/day), rabbits (3 to 50 mg/kg/day), and monkeys (1 to 3 mg/kg/day) before and during gestation, no teratogenic effects were seen.
◉ Summary of Use during Lactation:Because there is no published experience with thiothixene during breastfeeding, other antipsychotic agents are preferred.
◉ Effects in Breastfed Infants:Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk:Thiothixene has caused galactorrhea. Hyperprolactinemia appears to be the cause of the galactorrhea. The hyperprolactinemia is caused by the drug's dopamine-blocking action in the tuberoinfundibular pathway. The prolactin level in a mother with established lactation may not affect her ability to breastfeed.
Hepatic microsomal enzyme inducing agents, such as carbamazepine, were found to significantly increase the clearance of thiothixene. Patients receiving these drugs should be observed for signs of reduced thiothixene effectiveness.
In this study healthy volunteers received thiothixene with and without a 3-day pretreatment with paroxetine to determine if paroxetine decreased the clearance of thiothixene. Ten healthy medication-free volunteers (4 women and 6 men, mean age 38 +/- 12 years) were randomized to receive a single 20 mg oral dose of thiothixene on two separate occasions. On one occasion thiothixene was given concurrently, and following 3 days of pre-treatment with oral paroxetine (20 mg/day). On the other occasion thiothixene was given without paroxetine pre-treatment. The two study days were separated by a minimum period of 2 weeks. On both study days, after the administration of thiothixene, 10 mL blood samples were collected over the next 72 hr. None of the pharmacokinetic parameters of thiothixene were significantly altered by a 3-day treatment with paroxetine. It is likely that the CYP2D6 isoenzyme is not responsible for a high proportion of thiothixene clearance, but one cannot exclude the possibility that a longer paroxetine pretreatment might have caused some inhibition of thiothixene clearance.
Fifty-nine plasma thiothixene concentrations were measured in 42 patients as part of routine therapeutic drug monitoring. Data collection included concomitant medications, smoking history, and demographic variables. A retrospective analysis was performed to assess the effect of these parameters on oral thiothixene clearance. When groups of patients were categorized by concomitant medications (i.e., no interacting drugs, enzyme/clearance inducers, and enzyme/clearance inhibitors), thiothixene clearance was found to be significantly increased by enzyme inducing drugs (e.g., anticonvulsants) and decreased by clearance inhibiting agents (e.g., cimetidine). Tobacco smoking significantly increased the hepatic clearance of thiothixene within the no interactions and inhibitor groups, but not in the inducer group. Significantly more patients in the inducer group had nondetectable plasma concentrations of thiothixene than the other groups. When the entire patient population was dichotomized by age, patients less than 50 years old had a significantly greater mean clearance (48.2 +/- 37.8 liters/min) versus those greater than or equal to 50 (20.0 +/- 12.6 liters/min). Men in this cohort exhibited a significantly higher clearance (49.2 +/- 38.7 liters/min) than did the women (22.0 +/- 13.5 liters/min). By taking into account these potential sources of pharmacokinetic variability when monitoring plasma thiothixene concentrations, more appropriate dosing of thiothixene may be achieved. Controlled, prospective studies are needed to validate these findings.
Thiothixene is widely distributed into body tissues and may remain in the body for several weeks following administration.
来源:Hazardous Substances Data Bank (HSDB)
吸收、分配和排泄
Thiothixene is well absorbed from the GI tract. Therapeutic response may occur within a few days to several weeks following oral administration of the drug. Plasma concentrations required for therapeutic effects are not known.
硫噻嗪从胃肠道吸收良好。口服给药后，治疗反应可能在几天到几周内出现。治疗所需血浆浓度尚不清楚。
Thiothixene is well absorbed from the GI tract. Therapeutic response may occur within a few days to several weeks following oral administration of the drug. Plasma concentrations required for therapeutic effects are not known.
Two experiments are reported in which acute single test dose levels of thiothixene (Navane) were correlated with age. In the first study 20 mg oral doses were given to 28 male subjects and serum levels were drawn 2 hr later. Mean age was 30 and correlation of serum level with age was 0.43, P less than 0.02. In a second older group with a mean age of 41, 10 mg oral doses were given to 25 subjects. A correlation with age of 0.41, P less than 0.05 was obtained with age. In prior work such acute levels have been found to correlate with steady-state serum levels and with clinical response to the medication. ...
