Thioxanthene antipsychotics

Thiothixene (2 mg t.i.d. in mild cases) is indicated in the management of psychotic disorders. Thiothixene and chlor-prothixene are thioxanthene antipsychotics. Their select pharmacological properties are compared with chlorprom-azine and haloperidol and are shown in Table 2. 

The answer is b. (Katzung, p 4822) Haloperidol, a butyrophenone, is by far the most likely antipsychotic to produce extrapyramidal toxicides Other agents, such as piperazine (an aromatic phenothiazine), thiothixene (a thioxanthene), and pimozide (a diphenylbutyropiperidine) are comparitively less likely to produce extrapyramidal toxicity than haloperi-dol. The antagonism of dopamine in the nigrostriatal system might explain the Parkinson-like effects Both haloperidol and pimozide act mainly on D2 receptors, whereas thioridazine and piperazine act on ooadrenergie receptors, and have a less potent but definite effect on D2 receptors. 

Whatever the underlying causes may be, neuroleptic medications are the most effective treatment for schizophrenia. All antipsychotic medications have some form of dopamine receptor antagonism and they are distinguished by their chemical class. The phenothiazines include chlorpromazine (Thorazine), thioridazine (Mellaril), mesoridazine (Serentil), trifluoperazine (Stelazine), fluphenazine (Prolixin), and prochlorperazine (Compazine). The thioxanthenes include chlorprohixine (Taractan) and thiothixene (Navane). Butyrophenones are represented by haloperidol (Haldol). Loxapine (Loxitane) is a dibenzoxapine, and molindone (Moban) is a dihydroindolone. 

Other first generation (atypical) antipsychotics include thioxanthenes, haloperidol, pimozide, and loxapine. 

Flupentixol is an antipsychotic classified as a thioxanthene. Thioxanthenes have pronounced extra pyramidal side-effects. 

From the chemical point of view antipsychotic drugs are subdivided into six chemical groups, as well as to the group of non-classifiable drugs. They are phenothiazines (chlorpromazine, promazine, triflupromazine, acetophenazine, fluphenazine, perphenazine, prochlorpherazine, trifluoperazine, mesoridazine, and thioridazine), thioxanthenes... 

A number of different compounds of the piperidine and piperazine series with p-fluorobuty-rophenone group substitutions at the nitrogen atom display significant neuroleptic activity (haloperidol, trifluperidol, droperidol, methorin). There is a considerable interest in butyrophenone derivatives as antipsychotic agents as well as in anesthesiology. They exhibit pharmacological effects and a mechanism of action very similar to that of phenothiazines and thioxanthenes in that they block dopaminergic receptors. However, they are more selective with respect to D2 receptors. 

Teflutixol, a poly substituted piperazine-thioxanthene structure, neuroleptic and antipsychotic [55837-23-5],1709... 

Zuclopenthixol, a polysubstituted piperazine-thioxanthene structure, antipsychotic [53772-83-1],... 

Thioxanthenes, such as flupenthixol and clopenthixol, are similar in structure to the phenothiazines. The therapeutic effects are similar to those of the piperazine group. Antipsychotic thioxanthenes are thought to benefit psychotic conditions by blocking postsynaptic dopamine receptors in the brain. They also produce an alpha-adrenergic blocking effect and depress the release of most hypothalamic and hypophyseal hormones. However, the concentration of prolactin is increased due to blockade of prolactin inhibitory factor (PIF), which inhibits the release of prolactin from the pituitary gland. 

Use cautiously with other drugs that increase seizure risk (TCAs, lithium, phenothiazines, thioxanthenes, some antipsychotics)... 

Conventional antipsychotic (neuroleptic, thioxanthene, dopamine 2 antagonist)... 

Antipsychotics. Phenothiazines, butyrophenones and thioxanthenes are best avoided unless the indications are compelling amounts in milk are small but animal studies suggest adverse effects on the developing nervous system. In particular. 

Zovirax aciclovir. zucapsaicin capsaicin, zuclomifene clomiphene. zuclomiphene clomiphene. zuclopenthixol [ban, inn] (clopenthixol [ban, inn, usan] zuclopenthixol decanoate zuclopenthixol dihydrochloride Z-clopenthixol Clopixol ) is a thioxanthene with a piperizine side-chain, and has general properties similar to the phenothiazines, such as chlorpromazine. It is used as an oral ANTIPSYCHOTIC for the short-term management of acute psychotic and mania disorders, or the exacerbation of chronic psychotic disorders. The decanoate and hydrochloride forms can be given by deep intramuscular injection particularly for maintainance of patients with agitated and aggressive behaviour, zuclopenthixol decanoate zuclopenthixol. zuclopenthixol dihydrochloride zuclopenthixol. Zumenon oestradiol. 

Antipsychotic drugs currently approved for clinical use in the United States are summarized in Table 10.1. Drugs classified as typical include the following several phenothiazine derivatives (1-9), the thioxanthene, thiothixene (10), the butyrophenone, haloperidol(ll),... 

Navane [Pfizer]. TM for the cis isomer of iV,iV-dnnethyl-9[3-4-methyl-l-piperazinyl-pro-pylidene]-thioxanthene-2-sulfonamide. An antipsychotic drug (thiothixene) said to be as effective as most of the phenothiazines. Approved by the FDA. 

Loxapine, a dibenzoxazepine compound, represents a new subclass of tricyclic antipsychotic agents, chemically distinct from the thioxanthenes, butyrophenones, and phe-nothiazines. Chemically, it is a 2-chloro-ll-(4-methyl-l-piperazinyl)-dibenz[b,f](l,4)-oxazepine. It is present in capsules as the succinate salt, and in the concentrate and parenteral forms primarily as the hydrochloride salt. 

---