Thorazine

Thorazine, the brand name for chlorpromazine, is a phenothiazine antipsychotic that helped inaugurate the era of modern psychopharmacology. Introduced in the 1950s, it became one of the first widely used antipsychotic medications and is credited with transforming the treatment of schizophrenia and related disorders, as well as contributing to a broader shift away from long-term psychiatric hospitalization.

Medical uses: Chlorpromazine is used to treat schizophrenia and other psychotic disorders, severe manic states, and, in some settings, agitation associated with delirium. It is also employed as an antiemetic in postoperative care and, less commonly, to treat intractable hiccups.

Mechanism and pharmacology: The drug acts primarily as a dopamine D2 receptor antagonist in the brain, reducing dopaminergic neurotransmission in mesolimbic pathways implicated in psychosis. It also blocks several other receptors, including histamine H1, alpha-adrenergic, and muscarinic acetylcholine receptors, contributing to both its therapeutic effects and adverse effects.

Side effects and safety: Common adverse effects include extrapyramidal symptoms (acute dystonias, parkinsonism, akathisia), sedation, weight gain, and anticholinergic effects. Long-term use carries a risk of tardive dyskinesia. Additional risks include orthostatic hypotension, photosensitivity, metabolic changes, and rare but serious conditions such as neuroleptic malignant syndrome. Caution is advised in elderly patients and in those with cardiovascular or hepatic disease.

History and status: Thorazine is a historical cornerstone in psychiatry and helped pave the development of later antipsychotics. With the advent of atypical antipsychotics, its use has declined in many settings, but it remains available generically and is still used in certain indications and in some parts of the world.