Chlorpromazine 

Chlorpromazine (as chlorpromazine hydrochloride, abbreviated CPZ, marketed in the US as Thorazine, in Canada as "Stemetil" [Stemetil is a brand of prochlorperazine in most countries], Largactil in UK) is a phenothiazine antipsychotic, and the oldest in the antipsychotic family of drugs. It is a typical antipsychotic. It is principally used in the treatment of schizophrenia, though it has also been used to treat severe manic episodes in people with bipolar disorder. It has also been proven in stopping uncontrollable hiccups. Synthesized on December 11, 1950, chlorpromazine was the first drug developed with a specific antipsychotic action. Its use has been described as the single biggest advance in psychiatric treatment, with a dramatic effect on the prognosis of the inmates of asylums worldwide. It was the prototype for the phenothiazine class, which later grew to comprise several other agents. Its use today has been largely supplanted by the newer atypical antipsychotics such as olanzapine and quetiapine.

Chlorpromazine works on a variety of receptors in the central nervous system; these include anticholinergic, antidopaminergic and antihistamine effects as well as some antagonism of adrenergic receptors.[1] Chlorpromazine, along with many of the older antipsychotics which have minimal effect on the serotonergic pathways, is considered a typical antipsychotic.

Its receptor affinities result in a side-effect profile that is predominantly anticholinergic in nature: constipation, sedation, hypotension, and antiemetic properties. It also has anxiolytic (alleviation of anxiety) properties. Extrapyramidal side-effects that are common in many antipsychotics may occur, but are ameliorated by chlorpromazine's anticholinergic activity. They include akathisia and parkinsonian tremor, which can be very unpleasant though reversible. A more chronic side-effect is tardive dyskinesia, which may be irreversible in some patients.[2] Neuroleptic malignant syndrome is a rare though potentially fatal outcome of any antipsychotic use — about one in two thousand (0.05%) patients taking chlorpromazine may develop it. It is often administered in acute settings as a syrup, which has a faster onset of action than tablets. Parenteral administration is not generally recommended.