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Risperidone
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 5073
DrugBank APRD00187
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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Risperdal tablets

Risperidone (pronounced Ris-PEAR-rǐ-dōne) is an atypical antipsychotic used to treat schizophrenia (including adolescent schizophrenia), schizoaffective 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.

Contents

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 adolescents aged 5-16 years
  • it has also been used as a control drug for people with Tourette's syndrome and other tic disorders.

Risperidone was approved by the United States Food and Drug Administration (FDA) in 1993 for the treatment of schizophrenia.[2]

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 benzisoxazole and piperidine 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.[3] 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.[4] 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[5] and chronic use.[6]

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.[7] 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.[8]

Availability

Janssen's patent on Risperdal expired on December 29, 2007, opening the market for cheaper generic versions of the drug from other companies, and Janssen's exclusive marketing rights expired on June 29, 2008 (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 injection administered once every two weeks. It is also available as a wafer known in the United States and Canada as Risperdal M-Tabs and elsewhere as Risperdal Quicklets.

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."

Side effects

Risperidone has been associated with weight gain.[9] Other common side effects include severe anxiety, akathisia, sedation, dysphoria, insomnia, sexual dysfunction, low blood pressure, muscle stiffness, muscle pain, tremors, increased salivation, and stuffy nose.

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.[10][11] There is a higher association between pituitary neoplasms with use of risperidone and amisulpride than with other antipsychotic agents.[12] It is thought that once risperidone raises prolactin, it may cause prolactinoma, a benign tumor of the pituitary gland. Tumors, in general, aren't considered reversible. Medical therapy may help reduce tumor size and restore normal reproduction and pituitary function, however, dopamine agonists aren't 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.[13]

Risperidone can potentially cause tardive dyskinesia (TD),[14] extrapyramidal symptoms (EPS),[14] and neuroleptic malignant syndrome (NMS).[14] Risperidone may also trigger diabetes and more serious conditions of glucose metabolism, including ketoacidosis and hyperosmolar coma.[15]

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. The EPS are a consequence of increased release of dopamine from nigrostriatal neurons in the brain.

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, lingers 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 incompliant, or consenting patients who may have disorganized thinking and cannot remember to take their daily doses.[16] Doses range from 12.5 to 50 mg given as an intramuscular injection once every two weeks.

References

  1. ^ http://www.naminh.org/resources-medications-treatments-medications-risperdal.php
  2. ^ "Electronic Orange Book". Food and Drug Administration. April 2007. http://www.accessdata.fda.gov/scripts/cder/ob/docs/obdetail.cfm?Appl_No=020272&TABLE1=OB_Rx. Retrieved 2007-05-24. 
  3. ^ FDA (October 6, 2006). "FDA approves the first drug to treat irritability associated with autism, Risperdal". Press release. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2006/ucm108759.htm. Retrieved 2009-08-14. 
  4. ^ Scahill L (2008). "How do I decide whether or not to use medication for my child with autism? should I try behavior therapy first?". J Autism Dev Disord 38 (6): 1197–8. doi:10.1007/s10803-008-0573-7. PMID 18463973. 
  5. ^ AJ Giannini, GL Colapietro, DK Cook. Risperidone therapy in phencyclidine intoxication, Society for Neuroscience Abstracts. 22:77.12, 1996.
  6. ^ JF Gabbert,AJ Giannini. Dopaminergic/serotonergic actions of phencyclidine as a model for schizophrenia psychosis. American Journal of Therapeutics. 4:159-164, 1997.
  7. ^ Thomson A, Maltezos S, Paliokosta E, Xenitidis K (2009). "Risperidone for attention-deficit hyperactivity disorder in people with intellectual disabilities". Cochrane Database Syst Rev (2): CD007011. doi:10.1002/14651858.CD007011.pub2. PMID 19370667. 
  8. ^ Ballard C, Lana MM, Theodoulou M et al. (2008). "A randomised, blinded, placebo-controlled trial in dementia patients continuing or stopping neuroleptics (the DART-AD trial)". PLOS Medicine 5 (4): e76. doi:10.1371/journal.pmed.0050076. PMID 18384230. http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pmed.0050076. Lay summary – BBC News (2008-04-01). 
  9. ^ Newcomer JW (2005). "Second-generation (atypical) antipsychotics and metabolic effects: a comprehensive literature review". CNS Drugs 19 Suppl 1: 1–93. PMID 15998156. 
  10. ^ Byerly, M.; Suppes, T.; Tran, QV.; Baker, RA. (Dec 2007). "Clinical implications of antipsychotic-induced hyperprolactinemia in patients with schizophrenia spectrum or bipolar spectrum disorders: recent developments and current perspectives.". J Clin Psychopharmacol 27 (6): 639-61. doi:10.1097/jcp.0b013e31815ac4e5. PMID 18004132. 
  11. ^ Toren, P.; Ratner, S.; Laor, N.; Weizman, A. (2004). "Benefit-risk assessment of atypical antipsychotics in the treatment of schizophrenia and comorbid disorders in children and adolescents.". Drug Saf 27 (14): 1135-56. PMID 15554747. 
  12. ^ Doraiswamy, PM.; Schott, G.; Star, K.; Edwards, R.; Mueller-Oerlinghausen, B. (2007). "Atypical antipsychotics and pituitary neoplasms in the WHO database.". Psychopharmacol Bull 40 (1): 74-6. PMID 17285098. 
  13. ^ Szarfman A, Tonning J, Levine J, Doraiswamy P (2006). "Atypical antipsychotics and pituitary tumors: a pharmacovigilance study.". Pharmacotherapy 26 (6): 748–58. doi:10.1592/phco.26.6.748. PMID 16716128. 
  14. ^ a b c "Risperdal: Full U.S. Prescribing Information" (PDF). publisher=Ortho-McNeil-Janssen Pharmaceuticals. http://www.risperdal.com/risperdal/shared/pi/risperdal.pdf. Retrieved 2008-03-06. 
  15. ^ FDA (April 19, 2004). "FDA Warning Letter". Press release. http://www.fda.gov/ICECI/EnforcementActions/WarningLetters/2004/ucm146839.htm. Retrieved 2009-08-14. 
  16. ^ Antipsychotic Medications, About.com: Mental Health May 30, 2006

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