Thiothixene
Mechanism :
Thiothixene is a thioxanthene antipsychotic which elicits antipsychotic activity by postsynaptic blockade of CNS dopamine receptors resulting in inhibition of dopamine-mediated effects; also has alpha-adrenergic blocking activity.
Indication :
- For the management of schizophrenia
- Off-Label: Psychosis/agitation associated with dementia.
Contraindications :
Hypersensitivity to thiothixene or any component of the formulation; severe CNS depression; circulatory collapse; blood dyscrasias; coma.
Dosing :
Children ≥12 years and Adolescents:
Oral: Initial: Mild to moderate symptoms: 2 mg 3 times daily; usual dose 15 mg/day; severe symptoms: 5 mg twice daily; usual dose 20 to 30 mg/day. Maximum: 60 mg/day.
Adverse Effect :
Constipation, decreased sweating, drowsiness, extrapyramidal symptoms, increased appetite, orthostatic hypotension, photosensitivity, weight gain, xerostomia, agitation, allergic dermatitis, anticholinergic effects, anxiety, depression, dizziness, insomnia, lens opacities (prolonged use), rash, restlessness, sedation, tachycardia, weakness.
Interaction :
Dopamine: Thiothixene decreases effects of dopamine by pharmacodynamic antagonism.
Fentanyl: Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug.
Metoprolol, Propranolol: Either increases levels of the other by decreasing metabolism. Contraindicated. Not all beta blockers share this interaction
Ondansetron: Ondansetron and thiothixene both increase QTc interval. Avoid or Use Alternate Drug.
Hepatic Dose :
In hepatic impairment, drug metabolism is decreased, so monitor closely and reduce dose if needed.
If jaundice develops after drug use, stop therapy.