Chlorpromazine

Chlorpromazine (CPZ), marketed under the trade names Thorazine and Largactil among others, is an antipsychotic medication. It is primarily used to treat psychotic disorders such as schizophrenia. Other uses include the treatment of bipolar disorder, attention deficit hyperactivity disorder, nausea and vomiting, anxiety before surgery, and hiccups that do not improve following other measures. It can be given by mouth, by injection into a muscle, or into a vein. Chlorpromazine (CPZ), marketed under the trade names Thorazine and Largactil among others, is an antipsychotic medication. It is primarily used to treat psychotic disorders such as schizophrenia. Other uses include the treatment of bipolar disorder, attention deficit hyperactivity disorder, nausea and vomiting, anxiety before surgery, and hiccups that do not improve following other measures. It can be given by mouth, by injection into a muscle, or into a vein. Common side effects include movement problems, sleepiness, dry mouth, low blood pressure upon standing, and increased weight. Serious side effects may include the potentially permanent movement disorder tardive dyskinesia, neuroleptic malignant syndrome, and low white blood cell levels. In older people with psychosis as a result of dementia it may increase the risk of death. It is unclear if it is safe for use in pregnancy. Chlorpromazine is in the typical antipsychotic class. Its mechanism of action is not entirely clear but believed to be related to its ability as a dopamine antagonist. It also has anti-serotonergic and antihistaminergic properties. Chlorpromazine was discovered in 1950 and was the first antipsychotic. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Its introduction has been labeled as one of the great advances in the history of psychiatry. It is available as a generic medication. The wholesale cost in the developing world is between US$0.02 and US$0.12 per day. In the United States the wholesale costs is about US$7.80 per day as of 2019. Chlorpromazine is classified as a low-potency typical antipsychotic and in the past was used in the treatment of both acute and chronic psychoses, including schizophrenia and the manic phase of bipolar disorder, as well as amphetamine-induced psychosis. Low-potency antipsychotics have more anticholinergic side effects, such as dry mouth, sedation, and constipation, and lower rates of extrapyramidal side effects, while high-potency antipsychotics (such as haloperidol) have the reverse profile. In a 2013 comparison of 15 antipsychotics in schizophrenia, chlorpromazine demonstrated mild-standard effectiveness. It was 13% more effective than lurasidone and iloperidone, approximately as effective as ziprasidone and asenapine, and 12-16% less effective than haloperidol, quetiapine, and aripiprazole. Chlorpromazine has also been used in porphyria and as part of tetanus treatment. It still is recommended for short-term management of severe anxiety and psychotic aggression. Resistant and severe hiccups, severe nausea/emesis, and preanesthetic conditioning are other uses. Symptoms of delirium in hospitalized AIDS patients have been effectively treated with low doses of chlorpromazine. Chlorpromazine is occasionally used off-label for treatment of severe migraine. It is often, particularly as palliation, used in small doses to reduce nausea suffered by opioid-treated cancer patients and to intensify and prolong the analgesia of the opioids as well. In Germany, chlorpromazine still carries label indications for insomnia, severe pruritus, and preanesthesia. There appears to be a dose-dependent risk for seizures with chlorpromazine treatment. Tardive dyskinesia (involuntary, repetitive body movements) and akathisia (a feeling of inner restlessness and inability to stay still) are less commonly seen with chlorpromazine than they are with high potency typical antipsychotics such as haloperidol or trifluoperazine, and some evidence suggests that, with conservative dosing, the incidence of such effects for chlorpromazine may be comparable to that of newer agents such as risperidone or olanzapine.