Antipsychotics, also known as neuroleptics, are a class of psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), principally in schizophrenia but also in a range of other psychotic disorders. They are also the mainstay together with mood stabilizers in the treatment of bipolar disorder.
Prior research has shown that use of any antipsychotic is associated with smaller brain tissue volumes, including white matter reduction and that this brain shrinkage is dose dependent and time dependent. A more recent controlled trial suggests that second generation antipsychotics combined with intensive psychosocial therapy may potentially prevent pallidal brain volume loss in first episode psychosis.
The use of antipsychotics may result in many unwanted side effects such as involuntary movement disorders, gynecomastia, impotence, weight gain and metabolic syndrome. Long-term use can produce adverse effects such as tardive dyskinesia, tardive dystonia, and tardive akathisia.
First-generation antipsychotics (e.g. chlorpromazine), known as typical antipsychotics, were first introduced in the 1950s, and others were developed until the early 1970s. Second-generation antipsychotics, known as atypical antipsychotics, were introduced firstly with clozapine in the early 1970s followed by others (e.g. risperidone). Both generations of medication block receptors in the brain for dopamine, but atypicals tend to act on serotonin receptors as well.
Antipsychotics in the nursing home population are often overprescribed, often for the purposes of making it easier to handle dementia patients. Federal efforts to reduce the use of antipsychotics in US nursing homes has led to a nationwide decrease in their usage in 2012.
Certain second-generation antipsychotics are misused or abused for their sedative, tranquilizing, and (paradoxically) “hallucinogenic” effects. The most commonly second-generation antipsychotic implicated is quetiapine. In case reports, quetiapine has been abused in doses taken by mouth (which is how the drug is available from the manufacturer), but also crushed and insufflated or mixed with water for injection into a vein.
Olanzapine, another sedating second-generation antipsychotic, has also been misused for similar reasons. There is no standard treatment for antipsychotic abuse, though switching to a second-generation antipsychotic with less abuse potential (e.g. aripiprazole) has been used.