Risperidone (Page 12 of 13)

14.4 Irritability Associated with Autistic Disorder

Short-Term Efficacy

The efficacy of risperidone in the treatment of irritability associated with autistic disorder was established in two 8-week, placebo-controlled trials in children and adolescents (aged 5 to 16 years) who met the DSM-IV criteria for autistic disorder. Over 90% of these subjects were under 12 years of age and most weighed over 20 kg (16 kg to 104.3 kg).

Efficacy was evaluated using two assessment scales: the Aberrant Behavior Checklist (ABC) and the Clinical Global Impression — Change (CGI-C) scale. The primary outcome measure in both trials was the change from baseline to endpoint in the Irritability subscale of the ABC (ABC-I). The ABC-I subscale measured the emotional and behavioral symptoms of autism, including aggression towards others, deliberate self-injuriousness, temper tantrums, and quickly changing moods. The CGI-C rating at endpoint was a co-primary outcome measure in one of the studies.

The results of these trials are as follows:

(1) In one of the 8-week, placebo-controlled trials, children and adolescents with autistic disorder (n=101), aged 5 to 16 years, received twice daily doses of placebo or risperidone 0.5 mg/day to 3.5 mg/day on a weight-adjusted basis. Risperidone, starting at 0.25 mg/day or 0.5 mg/day depending on baseline weight (< 20 kg and ≥ 20 kg, respectively) and titrated to clinical response (mean modal dose of 1.9 mg/day, equivalent to 0.06 mg/kg/day), significantly improved scores on the ABC-I subscale and on the CGI-C scale compared with placebo.

(2) In the other 8-week, placebo-controlled trial in children with autistic disorder (n=55), aged 5 to 12 years, risperidone 0.02 to 0.06 mg/kg/day given once or twice daily, starting at 0.01 mg/kg/day and titrated to clinical response (mean modal dose of 0.05 mg/kg/day, equivalent to 1.4 mg/day), significantly improved scores on the ABC-I subscale compared with placebo.

A third trial was a 6-week, multicenter, randomized, double-blind, placebo-controlled, fixed-dose study to evaluate the efficacy and safety of a lower than recommended dose of risperidone in subjects (N=96) 5 to 17 years of age with autistic disorder (defined by DSM-IV criteria) and associated irritability and related behavioral symptoms. Approximately 77% of patients were younger than 12 years of age (mean age = 9), and 88% were male. Most patients (73%) weighed less than 45 kg (mean weight = 40 kg). Approximately 90% of patients were antipsychotic-naïve before entering the study.

There were two weight-based, fixed doses of risperidone (high-dose and low-dose). The high dose was 1.25 mg per day for patients weighing 20 to < 45 kg, and it was 1.75 mg per day for patients weighing > 45 kg. The low dose was 0.125 mg per day for patients weighing 20 to < 45 kg, and it was 0.175 mg per day for patients weighing > 45 kg. The dose was administered once daily in the morning, or in the evening if sedation occurred.

The primary efficacy endpoint was the mean change in the Aberrant Behavior Checklist – Irritability subscale (ABC-I) score from baseline to the end of Week 6. The study demonstrated the efficacy of high-dose risperidone, as measured by the mean change in ABC-I score. It did not demonstrate efficacy for low-dose risperidone. The mean baseline ABC-I scores were 29 in the placebo group (n=35), 27 in the risperidone low-dose group (n=30), and 28 in the risperidone high-dose group (n=31). The mean changes in ABC-I scores were -3.5, -7.4, and -12.4 in the placebo, low-dose, and high-dose group respectively. The results in the high-dose group were statistically significant (p < 0.001) but not in the low-dose group (p=0.164).

Long-Term Efficacy

Following completion of the first 8-week double-blind study, 63 patients entered an open-label study extension where they were treated with risperidone for 4 or 6 months (depending on whether they received risperidone or placebo in the double-blind study). During this open-label treatment period, patients were maintained on a mean modal dose of risperidone of 1.8 mg/day to 2.1 mg/day (equivalent to 0.05 mg/kg/day to 0.07 mg/kg/day).

Patients who maintained their positive response to risperidone (response was defined as ≥ 25% improvement on the ABC-I subscale and a CGI-C rating of ‘much improved’ or ‘very much improved’) during the 4 to 6 month open-label treatment phase for about 140 days, on average, were randomized to receive risperidone or placebo during an 8-week, double-blind withdrawal study (n=39 of the 63 patients). A pre-planned interim analysis of data from patients who completed the withdrawal study (n=32), undertaken by an independent Data Safety Monitoring Board, demonstrated a significantly lower relapse rate in the risperidone group compared with the placebo group. Based on the interim analysis results, the study was terminated due to demonstration of a statistically significant effect on relapse prevention. Relapse was defined as ≥ 25% worsening on the most recent assessment of the ABC-I subscale (in relation to baseline of the randomized withdrawal phase).


16.1 How Supplied

Risperidone Tablets USP, 0.25 mg, are supplied as Yellow, round, biconvex, film coated tablet debossed with ‘r’ on one side and Plain on other side.

They are available as follows:

Bottles of 500: NDC 42291-908-50

Risperidone Tablets USP, 0.5 mg, are supplied as Brown, round, biconvex, film coated tablet debossed with ‘r 5’ on one side and Plain on other side.

They are available as follows:

Bottles of 500: NDC 42291-909-50

Risperidone Tablets USP, 1 mg, are supplied as White, round, biconvex, film coated tablet debossed with ‘r 1’ on one side and Plain on other side.

They are available as follows:

Bottles of 500: NDC 42291-910-50

Risperidone Tablets USP, 2 mg, are supplied as Orange, round, biconvex, film coated tablet debossed with ‘r 2’ on one side and Plain on other side.

They are available as follows:

Bottles of 500: NDC 42291-911-50

Risperidone Tablets USP, 3 mg, are supplied as Yellow, round, biconvex, film coated tablet debossed with ‘r 3’ on one side and Plain on other side.

They are available as follows:

Bottles of 500: NDC 42291-912-50

Risperidone Tablets USP, 4 mg, are supplied as Green, round, biconvex, film coated tablet debossed with ‘r 4’ on one side and Plain on other side.

They are available as follows:

Bottles of 500: NDC 42291-913-50

16.2 Storage and Handling

Risperidone tablets should be stored at 20° to 25°C (68°to 77°F); excursions permitted between 15° to 30°C (59° to 86°F) [see USP controlled room temperature]. Protect from light and moisture.

Keep out of reach of children.


Physicians are advised to discuss the following issues with patients for whom they prescribe risperidone.

Neuroleptic Malignant Syndrome (NMS)

Counsel patients about a potentially fatal adverse reaction, Neuroleptic Malignant Syndrome (NMS), that has been reported in association with administration of antipsychotic drugs. Advise patients, family members, or caregivers to contact the healthcare provider or report to the emergency room if they experience signs and symptoms of NMS, including hyperpyrexia, muscle rigidity, altered mental status including delirium, and evidence of autonomic instability (irregular pulse or blood pressure, tachycardia, diaphoresis, and cardiac dysrhythmia) [see Warnings and Precautions (5.3)] .

Tardive Dyskinesia

Counsel patients on the signs and symptoms of tardive dyskinesia and to contact their healthcare provider if these abnormal movements occur [see Warnings and Precautions (5.4)] .

Metabolic Changes

Educate patients about the risk of metabolic changes, how to recognize symptoms of hyperglycemia and diabetes mellitus, and the need for specific monitoring, including blood glucose, lipids, and weight [see Warnings and Precautions (5.5)] .

Orthostatic Hypotension

Educate patients about the risk of orthostatic hypotension and syncope, particularly at the time of initiating treatment, re-initiating treatment, or increasing the dose [see Warnings and Precautions (5.7)] .


Advise patients with a pre-existing low WBC or a history of drug induced leukopenia/neutropenia they should have their CBC monitored while taking risperidone [see Warnings and Precautions (5.9)] .


Counsel patients on signs and symptoms of hyperprolactinemia that may be associated with chronic use of risperidone. Advise them to seek medical attention if they experience any of the following: amenorrhea or galactorrhea in females, erectile dysfunction or gynecomastia in males. [See Warnings and Precautions (5.6)] .

Interference with Cognitive and Motor Performance

Caution patients about performing activities requiring mental alertness, such as operating hazardous machinery, or operating a motor vehicle until they are reasonably certain that risperidone therapy does not affect them adversely [see Warnings and Precautions (5.10)] .


Advise patients of the possibility of painful or prolonged penile erections (priapism). Instruct the patient to seek immediate medical attention in the event of priapism [ Warnings and Precautions (5.13)] .

Heat Exposure and Dehydration

Counsel patients regarding appropriate care in avoiding overheating and dehydration [see Warnings and Precautions (5.14)] .

Concomitant Medication

Advise patients to inform their healthcare providers if they are taking, or plan to take any prescription or over-the-counter drugs, as there is a potential for interactions [see Drug Interactions (7)] .


Advise patients to avoid alcohol while taking risperidone [see Drug Interactions (7.2)] .


Advise patients to notify their healthcare provider if they become pregnant or intend to become pregnant during treatment with risperidone. Advise patients that risperidone may cause extrapyramidal and/or withdrawal symptoms in a neonate. Advise patients that there is a pregnancy registry that monitors pregnancy outcomes in women exposed to risperidone during pregnancy [see Use in Specific Populations (8.1)] .


Advise breastfeeding women using risperidone to monitor infants for somnolence, failure to thrive, jitteriness, and extrapyramidal symptoms (tremors and abnormal muscle movements) and to seek medical care if they notice these signs [see Use in Specific Populations (8.2)] .


Advise females of reproductive potential that risperidone may impair fertility due to an increase in serum prolactin levels. The effects on fertility are reversible [see Use in Specific Populations (8.3)].

Manufactured for: AvKARE

Pulaski, TN 38478

Manufactured by:

Amneal Pharmaceuticals of New York, LLC

Brookhaven, NY 11719

Mfg. Rev. 08-2021-00 AV 08/21

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