Thiothixene

Generic name:

Thiothixene

Drug class:

Typical antipsychotic (thioxanthene derivative)

Dosage form:

Capsules: 5 mg, 10 mg, 25 mg

Root of administration:

Oral

Dose:

Typical adult initial: 2–4 mg twice daily, gradually increased; usual range 5–60 mg/day divided; maximum 60 mg/day. Adjust based on response and tolerance. Pediatrics and geriatrics: lower dosing. Varies by indication; consult label.

Mechanism of action:

Primarily antagonizes dopamine D2 receptors in the central nervous system; also antagonizes alpha-1 adrenergic and histamine H1 receptors, with lesser muscarinic receptor blockade, producing antipsychotic and sedative effects.

Drug usage cases:

• Schizophrenia (positive symptoms)
• Schizoaffective disorder
• Acute psychosis
• Adjunctive treatment in mania (off-label)
• Severe agitation or behavioral disturbances (off-label)
• Delirium (off-label)

Drug contra indications:

• Hypersensitivity to thiothixene or phenothiazines
• Comatose or severely depressed central nervous system states
• Bone marrow depression
• Subcortical brain damage
• Severe cardiovascular disease or known QT prolongation
• Angle-closure glaucoma
• Paralytic ileus
• Pheochromocytoma
• Breast cancer (history, due to hyperprolactinemia risk)

Side effects:

• Extrapyramidal symptoms: acute dystonia, parkinsonism, akathisia, tardive dyskinesia
• Neuroleptic malignant syndrome
• Orthostatic hypotension
• Anticholinergic effects: dry mouth, blurred vision, constipation, urinary retention
• Sedation, somnolence
• Weight gain, metabolic changes
• Hyperprolactinemia: galactorrhea, gynecomastia, amenorrhea
• QT prolongation, arrhythmias
• Seizures
• Photosensitivity reactions
• Skin rash
• Leukopenia, neutropenia, agranulocytosis (rare)
• Elevated liver enzymes
• Sexual dysfunction

Warnings:

• Increased mortality in elderly patients with dementia-related psychosis
• Risk of tardive dyskinesia with long-term use
• Risk of neuroleptic malignant syndrome
• Orthostatic hypotension risk; monitor blood pressure
• Lowered seizure threshold
• Photosensitivity; sun protection recommended
• Caution in cardiovascular, hepatic, or renal impairment
• Agranulocytosis risk; monitor blood counts periodically
• Avoid abrupt discontinuation to prevent withdrawal symptoms

Use during pregnancy or breastfeeding:

Pregnancy category C; administer only if benefits outweigh risks. Potential for neonatal extrapyramidal and withdrawal symptoms if used in third trimester; monitor neonate. Breastfeeding: excreted in breast milk; may cause sedation and extrapyramidal effects in infant; advise against breastfeeding or monitor closely.