An antipsychotic (or neuroleptic) is a tranquilizing psychiatric medication primarily used to manage psychosis (including delusions or hallucinations, as well as disordered thought), particularly in schizophrenia and bipolar disorder, and is increasingly being used in the management of non-psychotic disorders (ATC code N05A). A first generation of antipsychotics, known as typical antipsychotics, was discovered in the 1950s. Most of the drugs in the second generation, known as atypical antipsychotics, have been developed more recently, although the first atypical antipsychotic, clozapine, was discovered in the 1950s and introduced clinically in the 1970s. Both generations of antipsychotic medications tend to block receptors in the brain's dopamine pathways, but antipsychotic drugs encompass a wide range of receptor targets.
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| Antipsychotic Medications |
Medical uses of Antipsychotic Medications:
Common conditions with which antipsychotic medications might be used include
- schizophrenia,
- bipolar disorder
- and delusional disorder.
Antipsychotic Medications might also be used to counter psychosis associated with a wide range of other diagnoses, such as psychotic depression. However, not all symptoms require heavy medication and hallucinations and delusions should only be treated if they distress the patient or produce dangerous behaviors.
In addition, "antipsychotic medications" are increasingly used to treat non-psychotic disorders. For example, they are sometimes used off-label to manage aspects of Tourette syndrome orautism spectrum disorders. They have multiple off-label uses as an augmentation agent (i.e. in addition to another medication), for example in "treatment-resistant" depression or OCD. Despite the name, the off-label use of "antipsychotics" is said to involve deploying them as antidepressants, anti-anxiety drugs, mood stabilizers, cognitive enhancers, anti-aggressive, anti-impulsive, anti-suicidal and hypnotic (sleep) medications.
Antipsychotics Side effects:
- Antipsychotics, particularly atypicals, appear to cause diabetes mellitus and fatal diabetic ketoacidosis, especially (in US studies) in African Americans.
- Antipsychotics may cause pancreatitis.
- The atypical antipsychotics (especially olanzapine and clozapine) seem to (due to occupancy of the histamine receptor) cause weight gain more commonly than the typical antipsychotics. The well-documented metabolic side effects associated with weight gain include diabetes, which can be life-threatening.
- Antipsychotics increase the likelihood of a fatal heart attack, with the risk of death increasing with dose and the length of time on the drug.
Antipsychotics Withdrawal:
Withdrawal symptoms from antipsychotics may emerge during dosage reduction and discontinuation. Withdrawal symptoms can include:
- nausea,
- emesis,
- anorexia,
- diarrhea,rhinorrhea,
- diaphoresis,
- myalgia,
- paresthesia,
- anxiety,
- agitation,
- restlessness,
- and insomnia.
The psychological withdrawal symptoms can include psychosis, and can be mistaken for a relapse of the underlying disorder. Conversely, the withdrawal syndrome may also be a trigger for relapse. Better management of the withdrawal syndrome may improve the ability of individuals to discontinue antipsychotics.
Tardive dyskinesia can emerge as a physical withdrawal symptom, and may either gradually abate during the withdrawal phase, or become persistent. Withdrawal-related psychosis from antipsychotics is called "super sensitivity psychosis", and is attributed to increased number and sensitivity of brain dopamine receptors, due to blockade of dopaminergic receptors by the antipsychotics, which often leads to exacerbated symptoms in the absence of neuroleptic medication. Efficacy of antipsychotics may likewise be reduced over time, due to this development of drug tolerance.
Common Antipsychotic Medications :
- Clozapine (Clozaril) Antipsychotic - Requires weekly to biweekly complete blood count due to risk of agranulocytosis.
- Olanzapine (Zyprexa) Antipsychotic - Used to treat psychotic disorders including schizophrenia, acute manic episodes, and maintenance of bipolar disorder.
- Risperidone (Risperdal) Antipsychotic - Divided dosing is recommended until initial titration is completed, at which time the drug can be administered once daily. Used off-label to treat Tourette syndrome and anxiety disorder.