Risperidone

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 )] .

1 INDICATIONS AND USAGE Risperidone tablets are an 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 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 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 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 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) ] .

2 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

6 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 Gastroint

7 DRUG INTERACTIONS Carbamazepine and other enzyme inducers decrease plasma concentrations of risperidone. Increase the risperidone tablets dose up to double the patient’s usual dose. Titrate slowly. ( 7.1 ) Fluoxetine, paroxetine, and other CYP 2D6 enzyme inhibitors increase plasma concentrations of risperidone. Reduce the initial dose. Do not exceed a final dose of 8 mg per day of risperidone tablets. ( 7.1 ) 7.1 Pharmacokinetic-related Interactions The dose of risperidone tablets should be adjusted when used in combination with CYP2D6 enzyme inhibitors (e.g., fluoxetine, and paroxetine) and enzyme inducers (e.g., carbamazepine) [see Table 18 and Dosage and Administration (2.5) ]. Dose adjustment is not recommended for risperidone tablets when co-administered with ranitidine, cimetidine, amitriptyline, or erythromycin [see Table 18 ] . Table 18. Summary of Effect of Coadministered Drugs on Exposure to Active Moiety (Risperidone + 9-Hydroxy-Risperidone) in Healthy Subjects or Patients with Schizophrenia Coadministered Drug Dosing Schedule Effect on Active Moiety (Risperidone + 9- Hydroxy- Risperidone (Ratio*) Risperidone Dose Recommendation Coadministered Drug Risperidone AUC C max Enzyme (CYP2D6) inhibitors Fluoxetine 20 mg/day 2 or 3 mg twice daily 1.4 1.5 Re-evaluate dosing. Do not exceed 8 mg/day Paroxetine 10 mg/day 4 mg/day 1.3 - Re-evaluate dosing. Do not exceed 8 mg/day 20 mg/day 4 mg/day 1.6 - 40 mg/day 4 mg/day 1.8 - Enzyme (CYP3A/ PgP inducers) Inducers Carbamazepine 573 ± 168 mg/day 3 mg twice daily 0.51 0.55 Titrate dose upwards. Do not exceed twice the patient’s usual dose Enzyme (CYP3A) inhibitors Ranitidine 150 mg twice daily 1 mg single dose 1.2 1.4 Dose adjustment not needed Cimetidine 400 mg twice daily 1 mg single dose 1.1 1.3 Dose adjustment not needed Erythromycin 500 mg four times daily 1 mg single dose 1.1 0.94 Dose adjustment not needed Other Drugs Amitriptyline 50 mg twice daily 3 mg twice daily 1.2 1.1 Dose adjustment not Needed *Change relative to reference Effect of Risperidone on other drugs Lithium Repeated oral doses of risperidone tablets (3 mg twice daily) did not affect the exposure (AUC) or peak plasma concentrations (C max) of lithium (n=13). Dose adjustment for lithium is not recommended. Valproate Repeated oral doses of risperidone tablets (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 risperidone tablets. Dose adjustment for valproate is not recommended. Digoxin Risperidone tablets (0.25 mg twice daily) did not show a clinically relevant effect on the pharmacokinetics of digoxin. Dose adjustment for digoxin is not recommended. 7.2 Pharmacodynamic-related Interactions Centrally Acting Drugs and Alcohol Given the primary CNS effects of risperidone, caution should be used when risperidone tablets are taken in combination with other centrally acting drugs and alcohol. Drugs with Hypotensive Effects Because of its potential for inducing hypotension, risperidone tablets may enhance the hypotensive effects of other therapeutic agents with this potential. Levodopa and Dopamine Agonists Risperidone tablets may antagonize the effects of levodopa and dopamine agonists. 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 tablets and methylphenidate [see Adverse Reactions ( 6.2 )]. Clozapine Chronic administration of clozapine with risperidone tablets may decrease the clearance of risperidone.