Risperidone
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(Redirected from Risperdal)
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| Systematic (IUPAC) name | |
| 4-[2-[4-(6-fluorobenzo[d]isoxazol-3-yl)- 1-piperidyl]ethyl]-3-methyl- 2,6-diazabicyclo[4.4.0]deca-1,3-dien-5-one | |
| Identifiers | |
| CAS number | 106266-06-2 |
| ATC code | N05AX08 |
| PubChem | CID 5073 |
| IUPHAR ligand ID | 96 |
| DrugBank | DB00734 |
| ChemSpider | 4895 |
| Chemical data | |
| Formula | C23H27FN4O2 |
| Mol. mass | 410.485 g/mol |
| SMILES | eMolecules & PubChem |
| Pharmacokinetic data | |
| Bioavailability | 70% (oral) |
| Metabolism | Hepatic (CYP2D6-mediated) |
| Half-life | 3–20 hours |
| Excretion | Urinary |
| Therapeutic considerations | |
| Pregnancy cat. | C |
| Legal status | ℞ Prescription only |
| Routes | Oral and extended-release intramuscular injection |
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Risperidone (pronounced Ris-PEAR-rǐ-dōne) is an atypical antipsychotic used to treat schizophreniaschizoaffective disorder, the mixed and manic states associated with bipolar disorder, and irritability in children with autism. The drug was developed by Janssen-Cilag and first released in 1994[1]. It is sold under the trade name Risperdal in the Netherlands, United States, Canada, Australia, United Kingdom, Portugal, Spain, Turkey, New Zealand and several other countries, Risperdal or Ridal in New Zealand, Sizodon or Riscalin in India, Rispolept in Eastern Europe, and Russia, and Belivon, or Rispen elsewhere. (including adolescent schizophrenia),
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[edit] Indications and Uses
- treatment of schizophrenia in adults
- treatment of schizophrenia in adolescents aged 13-17 years
- alone or in combination with lithium or valproate, for the short-term treatment of acute manic or mixed episodes associated with Bipolar I Disorder in adults
- alone in the short-term treatment of acute manic or mixed episodes associated with Bipolar I Disorder in children and adolescents aged 10-17 years
- treatment of irritability associated with autistic disorder in children and young adults
- it has also been used as a control drug for people with tourette syndrome and other tic disorders.
- treatment of major depression with psychotic features
- cure persistent or intractable hiccups[2]
Risperidone was approved by the United States Food and Drug Administration (FDA) in 1993 for the treatment of schizophrenia.[3]
On August 22, 2007, risperidone was approved as the only drug agent available for treatment of schizophrenia in youth ages 13–17; it was also approved that same day for treatment of bipolar disorder in youth and children ages 10–17, joining lithium. Risperidone contains the functional groups of benzisoxazolepiperidine as part of its molecular structure. In 2003 the FDA approved risperidone for the short-term treatment of the mixed and manic states associated with bipolar disorder. In 2006 the FDA approved risperidone for the treatment of irritability in children and adolescents with autism.[4] The FDA's decision was based in part on a study of autistic children with severe and enduring problems of violent meltdowns, aggression, and self-injury; risperidone is not recommended for autistic children with mild aggression and explosive behavior without an enduring pattern.[5] Like other atypical antipsychotics, risperidone has also been used off-label for the treatment of anxiety disorders, such as obsessive-compulsive disorder; severe, treatment-resistant depression with or without psychotic features; tourette syndrome; disruptive behavior disorders in children; and eating disorders, among others. In two small studies risperidone was reported to successfully treat the symptoms of phencyclidine (PCP) psychosis due to acute intoxication[6] and chronic use.[7] and
A 2009 Cochrane Library review found no evidence from randomized controlled trials that risperidone is effective for the treatment of attention-deficit hyperactivity disorder (ADHD) in people with intellectual disabilities.[8] A multi-year UK study by the Alzheimer's Research Trust suggested that this and other neuroleptic anti-psychotic drugs commonly given to Alzheimer's patients with mild behavioural problems often made their condition worse. The study concluded that:
| “ | For most patients with AD, withdrawal of neuroleptics had no overall detrimental effect on functional and cognitive status and by some measures improved functional and cognitive status. Neuroleptics may have some value in the maintenance treatment of more severe neuropsychiatric symptoms, but this possibility must be weighed against the unwanted effects of therapy.[9] | ” |
[edit] Availability
Janssen's patent on Risperdal expired on December 29, 2003, opening the market for cheaper generic versions of the drug from other companies, and Janssen's exclusive marketing rights expired on June 29, 2004 (the result of a pediatric extension.)
Risperidone is available as a tablet in 0.25, 0.5, 1, 2, 3 and 4 mg sizes, as an oral solution (30ml, 1 mg/ml), and as a 12.5 mg, 25 mg, 37.5 mg and 50 mg ampoule Risperdal Consta, which is a depot injectionRisperdal M-Tabs and elsewhere as Risperdal Quicklets. administered once every two weeks. It is also available as a wafer known in the United States and Canada as
Risperidone became available as a generic drug in October 2008 from Teva Pharmaceuticals, Dr. Reddy's Laboratories, Inc. and Patriot Pharmaceutics. The Patriot generic is Janssen Pharmaceutical's "authorized generic pharmaceutical."
[edit] Side effects
Risperidone has been associated with weight gain.[10] Other common side effects include akathisia, sedation, dysphoria, insomnia, sexual dysfunction, low blood pressure, high blood pressure, muscle stiffness, muscletremors, increased salivation, constipation, and stuffy nose. pain,
Many antipsychotics are known to cause hyperprolactinemia which may lead to hypogonadism-induced osteoporosis, galactorrhoea, gynaecomastia, irregular menstruation and sexual dysfunction. However, risperidone is known to increase prolactin to a greater extent than other atypical antipsychotics. Although lactation is possible in both sexes using other antipsychotic drugs, risperidone is the biggest offender.[11][12][13] It is thought that once risperidone raises prolactin, it may cause prolactinoma, a benign tumor of the pituitary gland. Tumors, in general, are not considered reversible. Medical therapy may help reduce tumor size and restore normal reproduction and pituitary function, however, dopamine agonists[14] There is a higher association between pituitary neoplasms with use of risperidone and amisulpride than with other antipsychotic agents. are not likely to be prescribed to antipsychotic users, thus, surgery or radiation treatment may be required. This condition may recur if the patient is switched to a different antipsychotic. Risperidone has been known to cause increased thoughts of suicide.
Risperidone can potentially cause tardive dyskinesia (TD),[15] extrapyramidal symptoms (EPS),[15] and neuroleptic malignant syndrome (NMS).[15] Risperidone may also trigger diabetes and more serious conditions of glucose metabolism, including ketoacidosis and hyperosmolar coma, according to an FDA Warning Letter issued to Janssen Pharmaceutica, Inc. on 19-Apr-04.[16]
[edit] Pharmacology
This drug belongs to a class of antipsychotic drugs known as atypical antipsychotics that have more pronounced serotonin antagonism than dopamine antagonism, but risperidone is unique in this class because it retains dopamine antagonism. It has high affinity for D2 dopaminergic receptors. It has actions at several 5-HT (serotonin) receptor subtypes. These are 5-HT2C, linked to weight gain, 5-HT2A,linked to its antipsychotic action and relief of some of the extrapyramidal side effects (EPS) experienced with the typical neuroleptics.
It reaches peak plasma levels quickly regardless of whether it is administered as a liquid or pill. Risperidone is metabolised fairly quickly, so the potential for nausea subsides usually in two to three hours. However, the active metabolite, 9-hydroxy-risperidone, which has similar pharmacodynamics to risperidone, remains in the body for much longer, and has been developed as an antipsychotic in its own right, called paliperidone.
An intramuscular preparation, marketed as Risperdal Consta, can be given once every two weeks. It is slowly released from the injection site. This method of administration may be used on sanctioned patients who are declining, or consenting patients who may have disorganized thinking and cannot remember to take their daily doses.[17] Doses range from 12.5 to 50 mg given as an intramuscular injection once every two weeks.
