Risperidone

INDICATIONS AND USAGE Risperidone orally disintegrating tablets are atypical antipsychotic indicated for: Treatment of schizophrenia ( 1.1 ) As monotherapy or adjunctive therapy with lithium or valproate, for the treatment of acute manic or mixed episodes associated with Bipolar I Disorder ( 1.2) Treatment of irritability associated with autistic disorder ( 1.3 ) 1.1 Schizophrenia Risperidone orally disintegrating tablets are indicated for the treatment of schizophrenia. Efficacy was established in 4 short-term trials in adults, 2 short-term trials in adolescents (ages 13 to 17 years), and one long-term maintenance trial in adults [see Clinical Studies (14.1) ] . 1.2 Bipolar Mania Monotherapy Risperidone orally disintegrating tablets are indicated for the treatment of acute manic or mixed episodes associated with Bipolar I Disorder. Efficacy was established in 2 short-term trials in adults and one short-term trial in children and adolescents (ages 10 to 17 years) [see Clinical Studies (14.2) ] . Adjunctive Therapy Risperidone orally disintegrating tablets adjunctive therapy with lithium or valproate is indicated for the treatment of acute manic or mixed episodes associated with Bipolar I Disorder. Efficacy was established in one short-term trial in adults [see Clinical Studies (14.3) ] . 1.3 Irritability Associated with Autistic Disorder Risperidone orally disintegrating tablets are indicated for the treatment of irritability associated with autistic disorder, including symptoms of aggression towards others, deliberate self-injuriousness, temper tantrums, and quickly changing moods. Efficacy was established in 3 short-term trials in children and adolescents (ages 5 to 17 years) [see Clinical Studies (14.4) ] .

DOSAGE AND ADMINISTRATION Table 1. Recommended Daily Dosage by Indication Initial Dose Titration (Increments) Target Dose Effective Dose Range Schizophrenia: adults ( 2.1 ) 2 mg 1 to 2 mg 4 to 8 mg 4 to 16 mg Schizophrenia: adolescents ( 2.2 ) 0.5 mg 0.5 to 1 mg 3 mg 1 to 6 mg Bipolar mania: adults ( 2.2 ) 2 to 3 mg 1 mg 1 to 6 mg 1 to 6 mg Bipolar mania: children and adolescents ( 2.2 ) 0.5 mg 0.5 to 1 mg 1 to 2.5 mg 1 to 6 mg Irritability in autistic disorder ( 2.3 ) 0.25 mg Can increase to 0.5 mg by Day 4: (body weight less than 20 kg) 0.5 mg Can increase to 1 mg by Day 4: (body weight greater than or equal to 20 kg) After Day 4, at intervals of > 2 weeks: 0.25 mg (body weight less than 20 kg) 0.5 mg (body weight greater than or equal to 20 kg) 0.5 mg: (body weight less than 20 kg) 1 mg: (body weight greater than or equal to 20 kg) 0.5 to 3 mg Severe Renal and Hepatic Impairment in Adults: use a lower starting dose of 0.5 mg twice daily. May increase to dosages above 1.5 mg twice daily at intervals of one week or longer. Recommended daily dosage: Initial Dose Target Dose Effective Dose Range Schizophrenia: adults ( 2.1 ) 2 mg 4 to 8 mg 4 to 16 mg Schizophrenia: adolescents ( 2.1 ) 0.5 mg 3 mg 1 to 6 mg Bipolar mania: Adults ( 2.2 ) 2 to 3 mg 1 to 6 mg 1 to 6 mg Bipolar mania: in children and adolescents ( 2.2 ) 0.5 mg 1 to 2.5 mg 1 to 6 mg Irritability associated with autistic disorder ( 2.3 ) 0.25 mg (Weight < 20 kg) 0.5 mg (Weight ≥20 kg) 0.5 mg (<20 kg) 1 mg (≥20 kg) 0.5 to 3 mg Severe Renal or Hepatic Impairment in Adults: Use a lower starting dose of 0.5 mg twice daily. May increase to dosages above 1.5 mg twice daily at intervals of at least one week. ( 2.4 ) 2.1 Schizophrenia Adults Usual Initial Dose Risperidone tablets can be administered once or twice daily. Initial dosing is 2 mg per day. May increase the dose at intervals of 24 hours or greater, in increments of 1 to 2 mg per day, as tolerated, to a recommended dose of 4 to 8 mg per day. In some patients, slower titration may be appropriate. Efficacy has been demonstrated in a range of 4 mg to 16 mg per day . However, doses above 6 mg per day for twice daily dosing were not demonstrated to be more efficacious than lower doses, were associated with more extrapyramidal symptoms and other adverse effects, and are generally not recommended. In a single study supporting once-daily dosing, the efficacy results were generally stronger for 8 mg than for 4 mg. The safety of doses above 16 mg per day has not been evaluated in clinical trials [see Clinical Studies (14.1) ]. Adolescents The initial dose is 0.5 mg once daily, administered as a single-daily dose in the morning or evening. The dose may be adjusted at intervals of 24 hours or greater, in increments of 0.5 mg or 1 mg per day, as tolerated, to a recommended dose of 3 mg per day. Although efficacy has been demonstrated in studies of adolescent patients with schizophrenia at doses between 1 mg and 6 mg per day, no additional benefit was observed above 3 mg per day, and higher doses were associated with more adverse events. Doses higher than 6 mg per day have not been studied. Patients experiencing persistent somnolence may benefit from administering half the daily dose twice daily. Maintenance Therapy While it is unknown how long a patient with schizophrenia should remain on risperidone tablets, the effectiveness of risperidone tablets 2 mg per day to 8 mg per day at delaying relapse was demonstrated in a controlled trial in adult patients who had been clinically stable for at least 4 weeks and were then followed for a period of 1 to 2 years [see Clinical Studies (14.1) ] . Both adult and adolescent patients who respond acutely should generally be maintained on their effective dose beyond the acute episode. Patients should be periodically reassessed to determine the need for maintenance treatment. Reinitiation of Treatment in Patients Previously Discontinued Although there are no data to specifically address reinitiation of treatment, it is recommended that after an interval off risperidone tablets, the initial titration schedule should be followed. Switching From Other Antipsychotics There are no systematically collected data to specifically address switching schizophrenic patients from other antipsychotics to risperidone tablets, or treating patients with concomitant antipsychotics. 2.2 Bipolar Mania Usual Dose Adults The inital dose range is 2 mg to 3 mg per day. The dose may be adjusted at intervals of 24 hours or greater, in increments of 1 mg per day. The effective dose range is 1 mg to 6 mg per day, as studied in the short-term, placebo-controlled trials. In these trials, short-term (3 week) anti-manic efficacy was demonstrated in a flexible dosage range of 1 mg to 6 mg per day [see Clinical Studies (14.2 , 14.3) ] . Risperidone tablets doses higher than 6 mg per day were not studied. Pediatrics The inital dose is 0.5 mg once daily, administered as a single-daily dose in the morning or evening. The dose may be adjusted at intervals of 24 hours or greater, in increments of 0.5 mg or 1 mg per day, as tolerated, to the recommended target dose of 1 mg to 2.5 mg per day. Although efficacy has been demonstrated in studies of pediatric patients with bipolar mania at doses between 0.5 mg and 6 mg per day, no additional benefit was observed above 2.5 mg per day, and higher doses were associated with more adverse events. Doses higher than 6 mg per day have not been studied. Patients experiencing persistent somnolence may benefit from administering half the daily dose twice daily. Maintenance Therapy There is no body of evidence available from controlled trials to guide a clinician in the longer-term management of a patient who improves during treatment of an acute manic episode with risperidone tablets. While it is generally agreed that pharmacological treatment beyond an acute response in mania is desirable, both for maintenance of the initial response and for prevention of new manic episodes, there are no systematically obtained data to support the use of risperidone tablets in such longer-term treatment (i.e., beyond 3 weeks). The physician who elects to use risperidone tablets for extended periods should periodically re-evaluate the long-term risks and benefits of the drug for the individual patient. 2.3 Irritability Associated with Autistic Disorder - Pediatrics (Children and Adolescents) The dosage of risperidone tablets should be individualized according to the response and tolerability of the patient. The total daily dose of risperidone tablets can be administered once daily, or half the total daily dose can be administered twice daily. For patients with body weight less than 20 kg, initiate dosing at 0.25 mg per day. For patients with body weight greater than or equal to 20 kg, initiate dosing at 0.5 mg per day. After a minimum of four days, the dose may be increased to the recommended dose of 0.5 mg per day for patients less than 20 kg and 1.0 mg per day for patients greater than or equal to 20 kg. Maintain this dose for a minimum of 14 days. In patients not achieving sufficient clinical response, the dose may be increased at intervals of 2 weeks or greater, in increments of 0.25 mg per day for patients less than 20 kg, or increments of 0.5 mg per day for patients greater than or equal to 20 kg. The effective dose range is 0.5 mg to 3 mg per day. No dosing data are available for children who weigh less than 15 kg. Once sufficient clinical response has been achieved and maintained, consider gradually lowering the dose to achieve the optimal balance of efficacy and safety. The physician who elects to use risperidone tablets for extended periods should periodically re-evaluate the long-term risks and benefits of the drug for the individual patient. Patients experiencing persistent somnolence may benefit from a once-daily dose administered at bedtime or administering half the daily dose twice daily, or a reduction of the dose. 2.4 Do

WARNINGS AND PRECAUTIONS Cerebrovascular events, including stroke, in elderly patients with dementia-related psychosis: Risperidone tablets are not approved for use in patients with dementia-related psychosis ( 5.2 ) Neuroleptic Malignant Syndrome: Manage with immediate discontinuation of risperidone tablets and close monitoring. ( 5.3 ) Tardive dyskinesia: Consider discontinuing risperidone tablets if clinically indicated. ( 5.4 ) Metabolic Changes: Atypical antipsychotic drugs have been associated with metabolic changes that may increase cardiovascular / cerebrovascular risk. These metabolic changes include hyperglycemia, dyslipidemia, and weight gain. ( 5.5 ) Hyperglycemia and Diabetes Mellitus: Monitor patients for symptoms of hyperglycemia including polydipsia, polyuria, polyphagia and weakness. Monitor glucose regularly in patients with diabetes or at risk for diabetes. ( 5.5 ) Dyslipidemia: Undesirable alterations have been observed in patients treated with atypical antipsychotics. ( 5.5 ) Weight Gain : Significant weight gain has been reported. Monitor weight gain. ( 5.5 ) Hyperprolactinemia: Prolactin elevations occur and persist during chronic administration. ( 5.6 ) Orthostatic hypotension: For patients at risk, consider a lower starting dose and slower titration. ( 5.7 ) Leukopenia, Neutropenia, and Agranulocytosis: Perform complete blood counts in patients with a history of clinically significant low white blood cell count (WBC). Consider discontinuing risperidone tablets if a clinically significant decline in WBC occurs in the absence of other causative factors. ( 5.9 ) Potential for cognitive and motor impairment: Use caution when operating machinery. ( 5.10 ) Seizures: Use cautiously in patients with a history of seizures or with conditions that lower the seizure threshold. ( 5.11 ) 5.1 Increased Mortality in Elderly Patients with Dementia-Related Psychosis Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Analyses of 17 placebo-controlled trials (modal duration of 10 weeks), largely in patients taking atypical antipsychotic drugs, revealed a risk of death in drug-treated patients of between 1.6 to 1.7 times the risk of death in placebo-treated patients. Over the course of a typical 10-week controlled trial, the rate of death in drug-treated patients was about 4.5%, compared to a rate of about 2.6% in the placebo group. Although the causes of death were varied, most of the deaths appeared to be either cardiovascular (e.g., heart failure, sudden death) or infectious (e.g., pneumonia) in nature. Observational studies suggest that, similar to atypical antipsychotic drugs, treatment with conventional antipsychotic drugs may increase mortality. The extent to which the findings of increased mortality in observational studies may be attributed to the antipsychotic drug as opposed to some characteristic(s) of the patients is not clear. In two of four placebo-controlled trials in elderly patients with dementia-related psychosis, a higher incidence of mortality was observed in patients treated with furosemide plus risperidone tablets when compared to patients treated with risperidone tablets alone or with placebo plus furosemide. No pathological mechanism has been identified to explain this finding, and no consistent pattern for cause of death was observed. Risperidone tablets are not approved for the treatment of dementia-related psychosis [see Boxed Warning ] . 5.2 Cerebrovascular Adverse Reactions, Including Stroke, in Elderly Patients with Dementia-Related Psychosis Cerebrovascular adverse reactions (e.g., stroke, transient ischemic attack), including fatalities, were reported in patients (mean age 85 years; range 73-97) in trials of risperidone in elderly patients with dementia-related psychosis. In placebo-controlled trials, there was a significantly higher incidence of cerebrovascular adverse events in patients treated with risperidone compared to patients treated with placebo. Risperidone tablets are not approved for the treatment of patients with dementia-related psychosis. [see Boxed Warning and Warnings and Precautions (5.1) ] . 5.3 Neuroleptic Malignant Syndrome Neuroleptic Malignant Syndrome (NMS), a potentially fatal symptom complex, has been reported in association with antipsychotic drugs. Clinical manifestations of NMS are hyperpyrexia, muscle rigidity, altered mental status including delirium, and autonomic instability (irregular pulse or blood pressure, tachycardia, diaphoresis, and cardiac dysrhythmia). Additional signs may include elevated creatine phosphokinase, myoglobinuria (rhabdomyolysis), and acute renal failure. If NMS is suspected, immediately discontinue risperidone tablets and provide symptomatic treatment and monitoring. 5.4 Tardive Dyskinesia Tardive dyskinesia, a syndrome consisting of potentially irreversible, involuntary, dyskinetic movements, may develop in patients treated with antipsychotic drugs. Although the prevalence of the syndrome appears to be highest among the elderly, especially elderly women, it is impossible to predict which patients will develop the syndrome. Whether antipsychotic drug products differ in their potential to cause tardive dyskinesia is unknown. The risk of developing tardive dyskinesia and the likelihood that it will become irreversible increase with the duration of treatment and the cumulative dose. The syndrome can develop after relatively brief treatment periods, even at low doses. It may also occur after discontinuation of treatment. Tardive dyskinesia may remit, partially or completely, if antipsychotic treatment is discontinued. Antipsychotic treatment, itself, however, may suppress (or partially suppress) the signs and symptoms of the syndrome, possibly masking the underlying process. The effect that symptomatic suppression has upon the long-term course of the syndrome is unknown. Given these considerations, risperidone tablets should be prescribed in a manner that is most likely to minimize the occurrence of tardive dyskinesia. Chronic antipsychotic treatment should generally be reserved for patients: (1) who suffer from a chronic illness that is known to respond to antipsychotic drugs, and (2) for whom alternative, equally effective, but potentially less harmful treatments are not available or appropriate. In patients who do require chronic treatment, use the lowest dose and the shortest duration of treatment producing a satisfactory clinical response. Periodically reassess the need for continued treatment. If signs and symptoms of tardive dyskinesia appear in a patient on risperidone tablets, drug discontinuation should be considered. However, some patients may require treatment with risperidone tablets despite the presence of the syndrome. 5.5 Metabolic Changes Atypical antipsychotic drugs have been associated with metabolic changes that may increase cardiovascular/cerebrovascular risk. These metabolic changes include hyperglycemia, dyslipidemia, and body weight gain. While all of the drugs in the class have been shown to produce some metabolic changes, each drug has its own specific risk profile. Hyperglycemia and Diabetes Mellitus Hyperglycemia and diabetes mellitus, in some cases extreme and associated with ketoacidosis or hyperosmolar coma or death, have been reported in patients treated with atypical antipsychotics including risperidone tablets. Assessment of the relationship between atypical antipsychotic use and glucose abnormalities is complicated by the possibility of an increased background risk of diabetes mellitus in patients with schizophrenia and the increasing incidence of diabetes mellitus in the general population. Given these confounders, the relationship between atypical antipsychotic use and hyperglycemia-related adverse events is not completely understood. However, epidemiological studies suggest an increased risk of treatment-emergent hyperglycemia-related adverse events in patie

CONTRAINDICATIONS Risperidone Tablets, Oral Solution, or Orally Disintegrating Tablets are contraindicated in patients with a known hypersensitivity to either risperidone or paliperidone, or to any of the excipients in the Risperidone Tablets, Oral Solution, or Orally Disintegrating Tablets formulations. Hypersensitivity reactions, including anaphylactic reactions and angioedema, have been reported in patients treated with risperidone and in patients treated with paliperidone. Paliperidone is a metabolite of risperidone. Known hypersensitivity to risperidone, paliperidone, or to any excipients in Risperidone Tablets, Oral Solution, or Orally Disintegrating Tablets. ( 4 )

DRUG INTERACTIONS The interactions of Risperidone for Extended-Release Injectable Suspension with coadministration of other drugs have not been systematically evaluated. The drug interaction data provided in this section is based on studies with oral risperidone. Due to CNS effects, use caution when administering with other centrally-acting drugs. Avoid alcohol. ( 7.1 ) Due to hypotensive effects, hypotensive effects of other drugs with this potential may be enhanced. ( 7.2 ) Effects of levodopa and dopamine agonists may be antagonized. ( 7.3 ) Cimetidine and ranitidine increase the bioavailability of risperidone. ( 7.5 ) Clozapine may decrease clearance of risperidone. ( 7.7 ) Fluoxetine and paroxetine increase plasma concentrations of risperidone. ( 7.12 ) Carbamazepine and other enzyme inducers decrease plasma concentrations of risperidone. ( 7.13 ) 7.1 Centrally-Acting Drugs and Alcohol Given the primary CNS effects of risperidone, caution should be used when Risperidone for Extended-Release Injectable Suspension is administered in combination with other centrally-acting drugs or alcohol. 7.2 Drugs with Hypotensive Effects Because of its potential for inducing hypotension, Risperidone for Extended-Release Injectable Suspension may enhance the hypotensive effects of other therapeutic agents with this potential. 7.3 Levodopa and Dopamine Agonists Risperidone for Extended-Release Injectable Suspension may antagonize the effects of levodopa and dopamine agonists. 7.4 Amitriptyline Amitriptyline did not affect the pharmacokinetics of risperidone or of risperidone and 9-hydroxyrisperidone combined following concomitant administration with oral risperidone. 7.5 Cimetidine and Ranitidine Cimetidine and ranitidine increased the bioavailability of oral risperidone by 64% and 26%, respectively. However, cimetidine did not affect the AUC of risperidone and 9-hydroxyrisperidone combined, whereas ranitidine increased the AUC of risperidone and 9-hydroxyrisperidone combined by 20%. 7.6 Methylphenidate Concomitant use with methylphenidate, when there is change in dosage of either medication, may increase the risk of extrapyramidal symptoms (EPS). Monitor for symptoms of EPS with concomitant use of Risperidone for Extended-Release Injectable Suspension and methylphenidate [see Adverse Reactions (6.2)] . 7.7 Clozapine Chronic administration of clozapine with risperidone may decrease the clearance of risperidone. 7.8 Lithium Repeated doses of oral risperidone (3 mg twice daily) did not affect the exposure (AUC) or peak plasma concentrations (C max ) of lithium (N=13). 7.9 Valproate Repeated doses of oral risperidone (4 mg once daily) did not affect the pre-dose or average plasma concentrations and exposure (AUC) of valproate (1000 mg/day in three divided doses) compared to placebo (N=21). However, there was a 20% increase in valproate peak plasma concentration (C max ) after concomitant administration of oral risperidone. 7.10 Digoxin Oral risperidone (0.25 mg twice daily) did not show a clinically relevant effect on the pharmacokinetics of digoxin. 7.11 Topiramate Oral risperidone administered at doses from 1 to 6 mg/day concomitantly with topiramate 400 mg/day resulted in a 23% decrease in risperidone C max and a 33% decrease in risperidone AUC 0-12 hour at steady state. Minimal reductions in the exposure to risperidone and 9-hydroxyrisperidone combined, and no change for 9-hydroxyrisperidone were observed. This interaction is unlikely to be of clinical significance. There was no clinically relevant effect of oral risperidone on the pharmacokinetics of topiramate. 7.12 Drugs That Inhibit CYP 2D6 and Other CYP Isozymes Risperidone is metabolized to 9-hydroxyrisperidone by CYP 2D6, an enzyme that is polymorphic in the population and that can be inhibited by a variety of psychotropic and other drugs [see Clinical Pharmacology ( 12.3 )] . Drug interactions that reduce the metabolism of risperidone to 9-hydroxyrisperidone would increase the plasma concentrations of risperidone and lower the concentrations of 9-hydroxyrisperidone. Analysis of clinical studies involving a modest number of poor metabolizers (n≅70 patients) does not suggest that poor and extensive metabolizers have different rates of adverse effects. No comparison of effectiveness in the two groups has been made. In vitro studies showed that drugs metabolized by other CYP isozymes, including 1A1, 1A2, 2C9, 2C19, and 3A4, are only weak inhibitors of risperidone metabolism. Fluoxetine and Paroxetine Fluoxetine (20 mg once daily) and paroxetine (20 mg once daily), CYP 2D6 inhibitors, have been shown to increase the plasma concentration of risperidone 2.5 to 2.8 fold and 3 to 9 fold respectively. Fluoxetine did not affect the plasma concentration of 9-hydroxyrisperidone. Paroxetine lowered the concentration of 9-hydroxyrisperidone by about 10%. When either concomitant fluoxetine or paroxetine is initiated or discontinued, the physician should re-evaluate the dose of Risperidone for Extended-Release Injectable Suspension. When initiation of fluoxetine or paroxetine is considered, patients may be placed on a lower dose of Risperidone for Extended-Release Injectable Suspension between 2 to 4 weeks before the planned start of fluoxetine or paroxetine therapy to adjust for the expected increase in plasma concentrations of risperidone. When fluoxetine or paroxetine is initiated in patients receiving the recommended dose of 25 mg Risperidone for Extended-Release Injectable Suspension, it is recommended to continue treatment with the 25 mg dose unless clinical judgment necessitates lowering the Risperidone for Extended-Release Injectable Suspension dose to 12.5 mg or necessitates interruption of Risperidone for Extended-Release Injectable Suspension treatment. When Risperidone for Extended-Release Injectable Suspension is initiated in patients already receiving fluoxetine or paroxetine, a starting dose of 12.5 mg can be considered. The efficacy of the 12.5 mg dose has not been investigated in clinical trials [see also Dosage and Administration ( 2.5 )] . The effects of discontinuation of concomitant fluoxetine or paroxetine therapy on the pharmacokinetics of risperidone and 9-hydroxyrisperidone have not been studied. Erythromycin There were no significant interactions between oral risperidone and erythromycin. 7.13 Carbamazepine and Other CYP 3A4 Enzyme Inducers Carbamazepine coadministration with oral risperidone decreased the steady-state plasma concentrations of risperidone and 9-hydroxyrisperidone by about 50%. Plasma concentrations of carbamazepine did not appear to be affected. Coadministration of other known CYP 3A4 enzyme inducers (e.g., phenytoin, rifampin, and phenobarbital) with risperidone may cause similar decreases in the combined plasma concentrations of risperidone and 9-hydroxyrisperidone, which could lead to decreased efficacy of Risperidone for Extended-Release Injectable Suspension treatment. At the initiation of therapy with carbamazepine or other known hepatic enzyme inducers, patients should be closely monitored during the first 4 to 8 weeks, since the dose of Risperidone for Extended-Release Injectable Suspension may need to be adjusted. A dose increase, or additional oral risperidone, may need to be considered. On discontinuation of carbamazepine or other CYP 3A4 hepatic enzyme inducers, the dosage of Risperidone for Extended-Release Injectable Suspension should be re-evaluated and, if necessary, decreased. Patients may be placed on a lower dose of Risperidone for Extended-Release Injectable Suspension between 2 to 4 weeks before the planned discontinuation of carbamazepine or other CYP 3A4 enzyme inducers to adjust for the expected increase in plasma concentrations of risperidone plus 9-hydroxyrisperidone. For patients treated with the recommended dose of 25 mg Risperidone for Extended-Release Injectable Suspension and discontinuing from carbamazepine or other CYP 3A4 enzyme inducers, it i

ADVERSE REACTIONS The following are discussed in more detail in other sections of the labeling: • Increased mortality in elderly patients with dementia-related psychosis [see Boxed Warning and Warnings and Precautions ( 5.1 )] • Cerebrovascular adverse events, including stroke, in elderly patients with dementia-related psychosis [see Warnings and Precautions ( 5.2 )] • Neuroleptic malignant syndrome [see Warnings and Precautions ( 5.3 )] • Tardive dyskinesia [see Warnings and Precautions ( 5.4 )] • Metabolic Changes (Hyperglycemia and diabetes mellitus, Dyslipidemia, and Weight Gain) [see Warnings and Precautions ( 5.5 )] • Hyperprolactinemia [see Warnings and Precautions ( 5.6 )] • Orthostatic hypotension [see Warnings and Precautions ( 5.7 )] • Falls [see Warnings and Precautions ( 5.8 )] • Leukopenia, neutropenia, and agranulocytosis [see Warnings and Precautions ( 5.9 )] • Potential for cognitive and motor impairment [see Warnings and Precautions ( 5.10 )] • Seizures [see Warnings and Precautions ( 5.11 )] • Dysphagia [see Warnings and Precautions ( 5.12 )] • Priapism [see Warnings and Precautions ( 5.13 )] • Disruption of body temperature regulation [see Warnings and Precautions ( 5.14 )] The most common adverse reactions in clinical trials (> 5% and twice placebo) were parkinsonism, akathisia, dystonia, tremor, sedation, dizziness, anxiety, blurred vision, nausea, vomiting, upper abdominal pain, stomach discomfort, dyspepsia, diarrhea, salivary hypersecretion, constipation, dry mouth, increased appetite, increased weight, fatigue, rash, nasal congestion, upper respiratory tract infection, nasopharyngitis, and pharyngolaryngeal pain. The most common adverse reactions that were associated with discontinuation from clinical trials (causing discontinuation in >1% of adults and/or >2% of pediatrics) were nausea, somnolence, sedation, vomiting, dizziness, and akathisia [see Adverse Reactions, Discontinuations Due to Adverse Reactions ( 6.1 )] . The data described in this section are derived from a clinical trial database consisting of 9803 adult and pediatric patients exposed to one or more doses of risperidone tablets for the treatment of schizophrenia, bipolar mania, autistic disorder, and other psychiatric disorders in pediatrics and elderly patients with dementia. Of these 9803 patients, 2687 were patients who received risperidone tablets while participating in double-blind, placebo-controlled trials. The conditions and duration of treatment with risperidone tablets varied greatly and included (in overlapping categories) double-blind, fixed- and flexible-dose, placebo- or active-controlled studies and open-label phases of studies, inpatients and outpatients, and short-term (up to 12 weeks) and longer-term (up to 3 years) exposures. Safety was assessed by collecting adverse events and performing physical examinations, vital signs, body weights, laboratory analyses, and ECGs. The most common adverse reactions in clinical trials (≥5% and twice placebo) were parkinsonism, akathisia, dystonia, tremor, sedation, dizziness, anxiety, blurred vision, nausea, vomiting, upper abdominal pain, stomach discomfort, dyspepsia, diarrhea, salivary hypersecretion, constipation, dry mouth, increased appetite, increased weight, fatigue, rash, nasal congestion, upper respiratory tract infection, nasopharyngitis, and pharyngolaryngeal pain. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Ajanta Pharma USA Inc. at 855-664-7744 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. Commonly-Observed Adverse Reactions in Double-Blind, Placebo-Controlled Clinical Trials – Schizophrenia Adult Patients with Schizophrenia Table 8 lists the adverse reactions reported in 2% or more of risperidone tablets-treated adult patients with schizophrenia in three 4- to 8-week, double-blind, placebo-controlled trials. Table 8. Adverse Reactions in ≥2% of Risperidone Tablets-Treated Adult Patients (and greater than placebo) with Schizophrenia in Double-Blind, Placebo-Controlled Trials * Parkinsonism includes extrapyramidal disorder, musculoskeletal stiffness, parkinsonism, cogwheel rigidity, akinesia, bradykinesia, hypokinesia, masked facies, muscle rigidity, and Parkinson's disease. Akathisia includes akathisia and restlessness. Dystonia includes dystonia, muscle spasms, muscle contractions involuntary, muscle contracture, oculogyration, tongue paralysis. Tremor includes tremor and parkinsonian rest tremor. System/Organ Class Adverse Reaction Percentage of Patients Reporting Reaction Risperidone Tablets 2–8 mg per day (N=366) >8–16 mg per day (N=198) Placebo (N=225) Cardiac Disorders Tachycardia 1 3 0 Eye Disorders Vision blurred 3 1 1 Gastrointestinal Disorders Nausea 9 4 4 Constipation 8 9 6 Dyspepsia 8 6 5 Dry mouth 4 0 1 Abdominal discomfort 3 1 1 Salivary hypersecretion 2 1 <1 Diarrhea 2 1 1 General Disorders Fatigue 3 1 0 Chest pain 2 2 1 Asthenia 2 1 <1 Infections and Infestations Nasopharyngitis 3 4 3 Upper respiratory tract infection 2 3 1 Sinusitis 1 2 1 Urinary tract infection 1 3 0 Investigations Blood creatine phosphokinase increased 1 2 <1 Heart rate increased <1 2 0 Musculoskeletal and Connective Tissue Disorders Back pain 4 1 1 Arthralgia 2 3 <1 Pain in extremity 2 1 1 Nervous System Disorders Parkinsonism * 14 17 8 Akathisia * 10 10 3 Sedation 10 5 2 Dizziness 7 4 2 Dystonia * 3 4 2 Tremor * 2 3 1 Dizziness postural 2 0 0 Psychiatric Disorders Insomnia 32 25 27 Anxiety 16 11 11 Respiratory, Thoracic and Mediastinal Disorders Nasal congestion 4 6 2 Dyspnea 1 2 0 Epistaxis <1 2 0 Skin and Subcutaneous Tissue Disorders Rash 1 4 1 Dry skin 1 3 0 Vascular Disorders Orthostatic hypotension 2 1 0 Pediatric Patients with Schizophrenia Table 9 lists the adverse reactions reported in 5% or more of risperidone tablets-treated pediatric patients with schizophrenia in a 6-week double-blind, placebo-controlled trial. Table 9. Adverse Reactions in ≥5% of Risperidone Tablets-Treated Pediatric Patients (and greater than placebo) with Schizophrenia in a Double-Blind Trial * Parkinsonism includes extrapyramidal disorder, muscle rigidity, musculoskeletal stiffness, and hypokinesia. Akathisia includes akathisia and restlessness. Dystonia includes dystonia and oculogyration. System/Organ Class Adverse Reaction Percentage of Patients Reporting Reaction Risperidone Tablets 1–3 mg per day (N=55) 4–6 mg per day (N=51) Placebo (N=54) Gastrointestinal Disorders Salivary hypersecretion 0 10 2 Nervous System Disorders Sedation 24 12 4 Parkinsonism * 16 28 11 Tremor 11 10 6 Akathisia * 9 10 4 Dizziness 7 14 2 Dystonia * 2 6 0 Psychiatric Disorders Anxiety 7 6 0 Commonly-Observed Adverse Reactions in Double-Blind, Placebo-Controlled Clinical Trials – Bipolar Mania Adult Patients with Bipolar Mania Table 10 lists the adverse reactions reported in 2% or more of risperidone tablets-treated adult patients with bipolar mania in four 3-week, double-blind, placebo-controlled monotherapy trials. Table 10. Adverse Reactions in ≥2% of Risperidone Tablets-Treated Adult Patients (and greater than placebo) with Bipolar Mania in Double-Blind, Placebo-Controlled Monotherapy Trials * Parkinsonism includes extrapyramidal disorder, parkinsonism, musculoskeletal stiffness, hypokinesia, muscle rigidity, muscle tightness, bradykinesia, cogwheel rigidity. Akathisia includes akathisia and restlessness. Tremor includes tremor and parkinsonian rest tremor. Dystonia includes dystonia, muscle spasms, oculogyration, torticollis. System/Organ Class Adverse Reaction Percentage of Patients Reporting Reaction Risperidone Tablets 1–6 mg per day (N=448) Placebo (N=424) Eye Disorders Vision blurred 2 1 Gastrointestinal Disorders Nausea 5

12. CLINICAL PHARMACOLOGY 12.1 Mechanism of Action The mechanism of action of risperidone in schizophrenia is unclear. The drug's therapeutic activity in schizophrenia could be mediated through a combination of dopamine Type 2 (D 2 ) and serotonin Type 2 (5HT 2 ) receptor antagonism. The clinical effect from risperidone results from the combined concentrations of risperidone and its major metabolite, 9-hydroxyrisperidone (paliperidone) [see Clinical Pharmacology (12.3) ] . Antagonism at receptors other than D 2 and 5HT 2 may explain some of the other effects of risperidone [see Clinical Pharmacology (12.1) ] . 12.2 Pharmacodynamics Risperidone is a monoaminergic antagonist with high affinity (Ki of 0.12 to 7.3 nM) for the serotonin Type 2 (5HT 2 ), dopamine Type 2 (D 2 ), α 1 and α 2 adrenergic, and H 1 histaminergic receptors. Risperidone showed low to moderate affinity (Ki of 47 to 253 nM) for the serotonin 5HT 1C , 5HT 1D , and 5HT 1A receptors, weak affinity (Ki of 620 to 800 nM) for the dopamine D 1 and haloperidol-sensitive sigma site, and no affinity (when tested at concentrations greater than 10 -5 M) for cholinergic muscarinic or β 1 and β 2 adrenergic receptors. 12.3 Pharmacokinetics Absorption Risperidone is 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. Pharmacokinetic studies showed that risperidone orally disintegrating tablets and risperidone oral solution are bioequivalent to risperidone tablets. Plasma concentrations of risperidone, its major metabolite, 9-hydroxyrisperidone, and risperidone plus 9-hydroxyrisperidone are dose proportional over the dosing range of 1 to 16 mg daily (0.5 to 8 mg twice daily). Following oral administration of solution or tablet, mean peak plasma concentrations of risperidone occurred at about 1 hour. Peak concentrations of 9-hydroxyrisperidone occurred at about 3 hours in extensive metabolizers, and 17 hours in poor metabolizers. Steady-state concentrations of risperidone are reached in 1 day in extensive metabolizers and would be expected to reach steady-state in about 5 days in poor metabolizers. Steady-state concentrations of 9-hydroxyrisperidone are reached in 5 to 6 days (measured in extensive metabolizers). Food Effect Food does not affect either the rate or extent of absorption of risperidone. Thus, risperidone can be given with or without meals. Distribution Risperidone is rapidly distributed. The volume of distribution is 1 to 2 L/kg. In plasma, risperidone is bound to albumin and α 1 -acid glycoprotein. The plasma protein binding of risperidone is approximately 90%, and that of its major metabolite, 9-hydroxyrisperidone, is 77%. Neither risperidone nor 9-hydroxyrisperidone displaces each other from plasma binding sites. High therapeutic concentrations of sulfamethazine (100 mcg/mL), warfarin (10 mcg/mL), and carbamazepine (10 mcg/mL) caused only a slight increase in the free fraction of risperidone at 10 ng/mL and 9-hydroxyrisperidone at 50 ng/mL, changes of unknown clinical significance. Elimination Metabolism Risperidone is extensively metabolized in the liver. The main metabolic pathway is through hydroxylation of risperidone to 9-hydroxyrisperidone by the enzyme, CYP 2D6. A minor metabolic pathway is through N -dealkylation. The main metabolite, 9-hydroxyrisperidone, has similar pharmacological activity as risperidone. Consequently, the clinical effect of the drug results from the combined concentrations of risperidone plus 9-hydroxyrisperidone. CYP 2D6, also called debrisoquin hydroxylase, is the enzyme responsible for metabolism of many neuroleptics, antidepressants, antiarrhythmics, and other drugs. CYP 2D6 is subject to genetic polymorphism (about 6%-8% of Caucasians, and a very low percentage of Asians, have little or no activity and are “poor metabolizers”) and to inhibition by a variety of substrates and some non-substrates, notably quinidine. Extensive CYP 2D6 metabolizers convert risperidone rapidly into 9-hydroxyrisperidone, whereas poor CYP 2D6 metabolizers convert it much more slowly. Although extensive metabolizers have lower risperidone and higher 9-hydroxyrisperidone concentrations than poor metabolizers, the pharmacokinetics of risperidone and 9-hydroxyrisperidone combined, after single and multiple doses, are similar in extensive and poor metabolizers. Excretion Risperidone and its metabolites are eliminated via the urine and, to a much lesser extent, via the feces. As illustrated by a mass balance study of a single 1 mg oral dose of 14C-risperidone administered as solution to three healthy male volunteers, total recovery of radioactivity at 1 week was 84%, including 70% in the urine and 14% in the feces. The apparent half-life of risperidone was 3 hours (CV=30%) in extensive metabolizers and 20 hours (CV=40%) in poor metabolizers. The apparent half-life of 9-hydroxyrisperidone was about 21 hours (CV=20%) in extensive metabolizers and 30 hours (CV=25%) in poor metabolizers. The pharmacokinetics of risperidone and 9-hydroxyrisperidone combined, after single and multiple doses, were similar in extensive and poor metabolizers, with an overall mean elimination half-life of about 20 hours. Drug Interaction Studies Risperidone could be subject to two kinds of drug-drug interactions. First, inhibitors of CYP 2D6 interfere with conversion of risperidone to 9-hydroxyrisperidone [see Drug Interactions (7) ] . This occurs with quinidine, giving essentially all recipients a risperidone pharmacokinetic profile typical of poor metabolizers. The therapeutic benefits and adverse effects of risperidone in patients receiving quinidine have not been evaluated, but observations in a modest number (n&cong;70) of poor metabolizers given risperidonedo not suggest important differences between poor and extensive metabolizers. Second, co-administration of known enzyme inducers (e.g., carbamazepine, phenytoin, rifampin, and phenobarbital) with risperidonemay cause a decrease in the combined plasma concentrations of risperidone and 9-hydroxyrisperidone [see Drug Interactions (7) ] . It would also be possible for risperidone to interfere with metabolism of other drugs metabolized by CYP 2D6. Relatively weak binding of risperidone to the enzyme suggests this is unlikely [see Drug Interactions (7) ]. In vitro studies indicate that risperidone is a relatively weak inhibitor of CYP 2D6. Therefore, risperidone is not expected to substantially inhibit the clearance of drugs that are metabolized by this enzymatic pathway. In drug interaction studies, risperidone did not significantly affect the pharmacokinetics of donepezil and galantamine, which are metabolized by CYP 2D6. In vitro studies demonstrated that drugs metabolized by other CYP isozymes, including 1A1, 1A2, 2C9, 2C19, and 3A4, are only weak inhibitors of risperidone metabolism. Specific Populations Renal and Hepatic Impairment [See Use in Specific Populations ( 8.6 and 8.7 )]. Elderly 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. Dosing should be modified accordingly in the elderly patients [see Use in Specific Populations (8.5) ] . Pediatric The pharmacokinetics of risperidone and 9-hydroxyrisperidone in children were similar to those in adults after correcting for the difference in body weight. Race and Gender Effects No specific pharmacokinetic study was conducted to investigate race and gender effects, but a population pharmacokinetic analysis did not identify important differences in the disposition of risperidone due to gender (whether corrected for body weight or not) or race.