In psychiatry, an antipsychotic drug is any drug that is used to treat psychosis, which could be the result of several conditions. Since the invention of chlorpromazine in 1950, which was the first antipsychotic, a number of antipsychotics have been developed, some used more commonly than others. Antipsychotics are also the cause of several potential side-effects, which range from mild annoyances, such as nasal congestion, to deadly, such as neuroleptic malignant syndrome. The most practical drug for a patient requires careful consideration, and in most cases the patient must provide informed consent.
The typical antipsychotics where the first to be developed, with most being synthesized in the 1950s, and where the most commonly used until recently. Typical antipsychotics are believed to work mainly by blocking the brain's dopamine receptors, which have been implemented in psychotic states. Some examples of typical antipsychotics include:
The atypical antipsychotics are a newer group of drugs. Most where synthesized in the late 1990s and early 2000s. Since their introduction, atypicals have gradually been replacing typicals in the treatment of psychosis, mainly due to the fact that atypicals tend to have milder side-effect profiles. Atypicals are believed to work by blocking both the dopamine and serotonin receptors in the brain, however, the clinical importance of this is unknown. Examples of atypical antipsychotics include:
- Quetiapine (Seroquel or Seroquel XR)
- Ziprasidone (Geodon)
- Risperidone (Risperdal)
- Olanzapine (Zyprexa)
- Paliperidone (Invega)
Though atypicals are often touted as being milder than typicals, they often share side-effects with typicals, as well as having their own unique side-effect profile. Typicals are believed to cause neurologic problems, such as Tardive dyskinesia, more often, though atypicals can cause these problems as well. However, atypicals are linked to weight gain and diabetes while typicals are not. All antipsychotics can cause the potentially deadly neuroleptic malignant syndrome. Many antipsychotics are linked to low white counts as well.