Thiothixene

INDICATIONS & USAGE Thiothixene capsules are effective in the management of schizophrenia. Thiothixene capsules have not been evaluated in the management of behavioral complications in patients with mental retardation.

DOSAGE AND ADMINISTRATION Dosage of thiothixene capsules should be individually adjusted depending on the chronicity and severity of the symptoms of schizophrenia. In general, small doses should be used initially and gradually increased to the optimal effective level, based on patient response. Some patients have been successfully maintained on once-a-day thiothixene capsules therapy. The use of thiothixene capsules in children under 12 years of age is not recommended because safe conditions for its use have not been established. In milder conditions, an initial dose of 2 mg three times daily is recommended. If indicated, a subsequent increase to 15 mg/day total daily dose is often effective. In more severe conditions, an initial dose of 5 mg twice daily is recommended. The usual optimal dose is 20 mg to 30 mg daily. If indicated, an increase to 60 mg/day total daily dose is often effective. Exceeding a total daily dose of 60 mg rarely increases the beneficial response.

CONTRAINDICATIONS Thiothixene capsules are contraindicated in patients with circulatory collapse, comatose states, central nervous system depression due to any cause, and blood dyscrasias. Thiothixene capsules are contraindicated in individuals who have shown hypersensitivity to the drug. It is not known whether there is a cross sensitivity between the thioxanthenes and the phenothiazine derivatives, but this possibility should be considered.

ADVERSE REACTIONS NOTE : Not all of the following adverse reactions have been reported with thiothixene. However, since thiothixene has certain chemical and pharmacologic similarities to the phenothiazines, all of the known side effects and toxicity associated with phenothiazine therapy should be borne in mind when thiothixene is used. Cardiovascular Effects Tachycardia, hypotension, lightheadedness, and syncope. In the event hypotension occurs, epinephrine should not be used as a pressor agent since a paradoxical further lowering of blood pressure may result. Nonspecific EKG changes have been observed in some patients receiving thiothixene. These changes are usually reversible and frequently disappear on continued thiothixene therapy. The incidence of these changes is lower than that observed with some phenothiazines. The clinical significance of these changes is not known. CNS Effects Drowsiness, usually mild, may occur although it usually subsides with continuation of thiothixene therapy. The incidence of sedation appears similar to that of the piperazine group of phenothiazines but less than that of certain aliphatic phenothiazines. Restlessness, agitation and insomnia have been noted with thiothixene. Seizures and paradoxical exacerbation of psychotic symptoms have occurred with thiothixene infrequently. Hyperreflexia has been reported in infants delivered from mothers having received structurally related drugs. In addition, phenothiazine derivatives have been associated with cerebral edema and cerebrospinal fluid abnormalities. Extrapyramidal Symptoms Extrapyramidal symptoms, such as pseudoparkinsonism, akathisia and dystonia have been reported (see Dystonia, Class effect ). Management of these extra-pyramidal symptoms depends upon the type and severity. Rapid relief of acute symptoms may require the use of an injectable antiparkinson agent. More slowly emerging symptoms may be managed by reducing the dosage of thiothixene and/or administering an oral antiparkinson agent. Dystonia Class effect Symptoms of dystonia, prolonged abnormal contractions of muscle groups, may occur in susceptible individuals during the first few days of treatment. Dystonic symptoms include: spasm of the neck muscles, sometimes progressing to tightness of the throat, swallowing difficulty, difficulty breathing, and/or protrusion of the tongue. While these symptoms can occur at low doses, they occur more frequently and with greater severity with high potency and at higher doses of first generation antipsychotic drugs. An elevated risk of acute dystonia is observed in males and younger age groups. Persistent Tardive Dyskinesia As with all antipsychotic agents, tardive dyskinesia may appear in some patients on long-term therapy with thiothixene 1 or may occur after drug therapy has been discontinued. The syndrome is characterized by rhythmical involuntary movements of the tongue, face, mouth or jaw (e.g., protrusion of tongue, puffing of cheeks, puckering of mouth, chewing movements). Sometimes these may be accompanied by involuntary movements of extremities. Since early detection of tardive dyskinesia is important, patients should be monitored on an ongoing basis. It has been reported that fine vermicular movement of the tongue may be an early sign of the syndrome. If this or any other presentation of the syndrome is observed, the clinician should consider possible discontinuation of antipsychotic medication (see WARNINGS section). Hepatic Effects Elevations of serum transaminase and alkaline phosphatase, usually transient, have been infrequently observed in some patients. No clinically confirmed cases of jaundice attributable to thiothixene have been reported. Hematologic Effects As is true with certain other psychotropic drugs, leukopenia and leukocytosis, which are usually transient, can occur occasionally with thiothixene. Other antipsychotic drugs have been associated with agranulocytosis, eosinophilia, hemolytic anemia, thrombocytopenia and p …

DRUG INTERACTIONS 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 4,5 . Due to a possible additive effect with hypotensive agents, patients receiving these drugs should be observed closely for signs of excessive hypotension when thiothixene is added to their drug regimen 6 .

ACTIONS Thiothixene is an antipsychotic of the thioxanthene series. Thiothixene possesses certain chemical and pharmacological similarities to the piperazine phenothiazines and differences from the aliphatic group of phenothiazines.

DESCRIPTION Thiothixene is a thioxanthene derivative. Specifically, it is the cis isomer of N,N-dimethyl-9-[3-(4-methyl-1-piperazinyl)propylidene]thioxanthene-2-sulfonamide. It has a molecular formula C 23 H 29 N 3 O 2 S 2 and the molecular weight is 443.63 g/mol. The chemical structure is: The thioxanthenes differ from the phenothiazines by the replacement of nitrogen in the central ring with a carbon-linked side chain fixed in space in a rigid structural configuration. An N,N-dimethyl sulfonamide functional group is bonded to the thioxanthene nucleus. Each Thiothixene Capsules, USP contains 1 mg, 2 mg, 5 mg or 10 mg of thiothixene, USP and the following inactive ingredients: colloidal silicon dioxide, croscarmellose sodium, lactose monohydrate, magnesium stearate, microcrystalline cellulose, pregelatinized starch and sodium lauryl sulfate. Each empty hard gelatin capsule contains gelatin, iron oxide red, iron oxide yellow, purified water and titanium dioxide. In addition, the 1 mg hard gelatin capsule contains D&C yellow 10, FD&C blue 1 and FD&C red 40. The 2 mg hard gelatin capsule also contains D&C yellow 10 and ferrosoferric oxide. The 5 mg and 10 mg hard gelatin capsule also contains ferrosoferric oxide. The capsule is imprinted with black pharmaceutical ink which contains ferrosoferric oxide, potassium hydroxide, propylene glycol and shellac. structure

OVERDOSAGE Manifestations 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. Treatment Essentially symptomatic and supportive. Early gastric lavage is helpful. Keep patient under careful observation and maintain an open airway, since involvement of the extrapyramidal system may produce dysphagia and respiratory difficulty in severe overdosage. If hypotension occurs, the standard measures for managing circulatory shock should be used (intravenous (I.V.) fluids and/or vasoconstrictors). If a vasoconstrictor is needed, levarterenol and phenylephrine are the most suitable drugs. Other pressor agents, including epinephrine, are not recommended, since phenothiazine derivatives may reverse the usual pressor action of these agents and cause further lowering of blood pressure. If CNS depression is marked, symptomatic treatment is indicated. Extrapyramidal symptoms may be treated with antiparkinson drugs. There are no data on the use of peritoneal or hemodialysis, but they are known to be of little value in phenothiazine intoxication.

HOW SUPPLIED Thiothixene Capsules, USP are available containing 1 mg, 2 mg, 5 mg or 10 mg of thiothixene, USP. Thiothixene, USP 1 mg capsule is a size 4 hard gelatin capsule with a caramel opaque cap and a blue opaque body filled with white to off-white powder. The capsule is imprinted “014” on the cap and “novitium” on the body in black ink. They are available as below: NDC 70954-014-10 Bottle of 100 capsules NDC 70954-014-20 Bottle of 1000 capsules Thiothixene, USP 2 mg capsule is a size 4 hard gelatin capsule with a caramel opaque cap and a yellow opaque body filled with white to off-white powder. The capsule is imprinted “015” on the cap and “novitium” on the body in black ink. They are available as below: NDC 70954-015-10 Bottle of 100 capsules NDC 70954-015-20 Bottle of 1000 capsules NDC 70954-015-40 Unit dose blister packages of 100 (10 cards of 10 capsules each) Thiothixene, USP 5 mg capsule is a size 4 hard gelatin capsule with a caramel opaque cap and a white opaque body filled with white to off-white powder. The capsule is imprinted “016” on the cap and “novitium” on the body in black ink. They are available as below: NDC 70954-016-10 Bottle of 100 capsules NDC 70954-016-20 Bottle of 1000 capsules NDC 70954-016-40 Unit dose blister packages of 100 (10 cards of 10 capsules each) Thiothixene, USP 10 mg capsule is a size 4 hard gelatin capsule with a caramel opaque cap and a peach opaque body filled with white to off-white powder. The capsule is imprinted “017” on the cap and “novitium” on the body in black ink. They are available as below: NDC 70954-017-10 Bottle of 100 capsules NDC 70954-017-20 Bottle of 1000 capsules NDC 70954-017-40 Unit dose blister packages of 100 (10 cards of 10 capsules each) Store at 20° to 25°C (68° to 77°F). [See USP Controlled Room Temperature.] Protect from light. Preserve in tight, light-resistant container as defined in the USP.