2913 Risperidone Risperidone is an atypical antipsychotic medication approved in 1993. It is most often used to treat delusional psychosis (including schizophrenia), but risperidone (like other atypical antipsychotics) is also used to treat some forms of bipolar disorder, psychotic depression and Tourette syndrome. Generally lower doses are used for autistic spectrum disorders than are used for schizophrenia and other forms of psychosis; Risperidone is a very strong dopamine blocker (antagonist); Risperidone is a very strong dopamine blocker (antagonist); i.e., it inhibits functioning of postsynaptic dopamine receptors. An anxiolytic agent and a serotonin receptor agonist belonging to the azaspirodecanedione class of compounds. Its structure is unrelated to those of the benzodiazepines, but it has an efficacy comparable to diazepam; i.e., it inhibits functioning of postsynaptic dopamine receptors. Risperidone (Belivon, Rispen, Risperdal; in the United States) is an atypical antipsychotic medication. It was approved by the United States Food and Drug Administration (FDA) in 1993. It is most often used to treat delusional psychosis (including schizophrenia), but risperidone (like other atypical antipsychotics) is also used to treat some forms of bipolar disorder, psychotic depression and Tourette syndrome; risperidone has received approval from the Food and Drug Administration (FDA) for symptomatic treatment of irritability in autistic children and adolescents. Risperidone is now the most commonly prescribed antipsychotic medication in the United States. 106266-06-2 5073 C23H27FN4O2 410.211800 White powder. 170°C 2.8mg/L Well absorbed. The absolute oral bioavailability of risperidone is 70% (CV=25%). The relative oral bioavailability of risperidone from a tablet is 94% (CV=10%) when compared to a solution. Blockade of dopaminergic D2 receptors in the limbic system alleviates positive symptoms of schizophrenia such as hallucinations, delusions, and erratic behavior and speech. Blockade of serotonergic 5-HT₂ receptors in the mesocortical tract, causes an excess of dopamine and an increase in dopamine transmission, resulting in an increase in dopamine transmission and an elimination of core negative symptoms. Dopamine receptors in the nigrostriatal pathway are not affected by risperidone and extrapyramidal effects are avoided. Like other 5-HT₂ antagonists, risperidone also binds at alpha(1)-adrenergic receptors and, to a lesser extent, at histamine H1 and alpha(2)-adrenergic receptors. Extensively metabolized by hepatic cytochrome P450 2D6 isozyme to 9-hydroxyrisperidone, which has approximately the same receptor binding affinity as risperidone. Hydroxylation is dependent on debrisoquine 4-hydroxylase and metabolism is sensitive to genetic polymorphisms in debrisoquine 4-hydroxylase. Risperidone also undergoes N-dealkylation to a lesser extent. Route of Elimination: Risperidone is extensively metabolized in the liver.In healthy elderly subjects, renal clearance of both risperidone and 9-hydroxyrisperidone was decreased, and elimination half-lives were prolonged compared to young healthy subjects. Half Life: 20-24 hours LD₅₀=82.1mg/kg (orally in mice). No indication of carcinogenicity to humans (not listed by IARC). For the treatment of schizophrenia in adults and in adolescents, ages 13 to 17, and for the short-term treatment of manic or mixed episodes of bipolar I disorder in children and adolescents ages 10 to 17. May also be used to manage symptoms of inappropriate behavior due to aggression and/or psychosis in patients with severe dementia. Symptoms of overdose include drowsiness, sedation, tachycardia, hypotension, and extrapyramidal symptoms. In case of acute overdosage, establish and maintain an airway and ensure adequate oxygenation and ventilation. Gastric lavage (after intubation, if patient is unconscious) and administration of activated charcoal together with a laxative should be considered. The possibility of obtundation, seizures, or dystonic reaction of the head and neck following overdose may create a risk of aspiration with induced emesis. Cardiovascular monitoring should commence immediately and should include continuous electrocardiographic monitoring to detect possible arrhythmias. If antiarrhythmic therapy is administered, disopyramide, procainamide, and quinidine carry a theoretical hazard of QT-prolonging effects that might be additive to those of risperidone. Similarly, it is reasonable to expect that the alpha-blocking properties of bretylium might be additive to those of risperidone, resulting in problematic hypotension. There is no specific antidote to Risperidone. (L1712) 2009-07-21T20:27:30Z 2014-12-24T20:25:52Z Risperidone C06861 608902 8871 Risperidone DB00734 true CC1=C(CCN2CCC(CC2)C2=NOC3=C2C=CC(F)=C3)C(=O)N2CCCCC2=N1 C23H27FN4O2 InChI=1S/C23H27FN4O2/c1-15-18(23(29)28-10-3-2-4-21(28)25-15)9-13-27-11-7-16(8-12-27)22-19-6-5-17(24)14-20(19)30-26-22/h5-6,14,16H,2-4,7-13H2,1H3 InChIKey=RAPZEAPATHNIPO-UHFFFAOYSA-N 410.4845 410.211804333 Exogenous Solid 2.5 HMDB05020 CHEMBL85 4895 <p><a href="http://www.drugsyn.org/Risperidone.htm">DrugSyn.org</a></p>