Risperdal

(risperidone)

Risperdal (risperidone); not controlled

Summary

Risperdal is an atypical antipsychotic approved for irritability associated with autistic disorder from 5 years, bipolar I mania from 10 years, and schizophrenia from 13 years. Full D2 antagonism buys the strongest evidence in this library for reducing aggression and, in the same breath, the largest prolactin burden of any agent here. It follows optimised ADHD treatment, never replaces it. Not controlled; brand and generic.

Forms & Strengths

• Tablets: 0.25 mg, 0.5 mg, 1 mg, 2 mg, 3 mg, 4 mg
• Orally disintegrating tablets: 0.25 mg, 0.5 mg, 1 mg, 2 mg, 3 mg, 4 mg
• Oral solution: 1 mg/mL
• Long-acting injectables (Risperdal Consta, Perseris, Uzedy, Rykindo): separate labels

Dosing

• Age:
  • Autism irritability: 5 to 17 y/o; no dosing data under 15 kg
  • Bipolar I mania: 10 to 17 y/o and adults
  • Schizophrenia: 13 to 17 y/o and adults
• Onset: weeks to clinical effect; the pediatric ladder holds 14 days before further increase
• Duration: continuous with once-daily dosing; combined half-life 20 hours
• Initial Dose:
  • Autism irritability: 0.25 mg/day under 20 kg, 0.5 mg/day at 20 kg and over
  • Bipolar mania or schizophrenia, 10 to 17 y/o: 0.5 mg once daily
  • Adults: 2 mg/day schizophrenia, 2 to 3 mg/day bipolar mania
• Titration:
  • Autism irritability: after 4 days minimum, to 0.5 mg/day under 20 kg or 1 mg/day at 20 kg and over
  • Hold 14 days minimum, then increase every 2 weeks or more by 0.25 mg/day under 20 kg or 0.5 mg/day at 20 kg and over
  • Adolescents: 0.5 mg or 1 mg per day, at intervals of 24 hours or greater
  • Adults: 1 to 2 mg/day schizophrenia, 1 mg/day bipolar mania
• Max Dose:
  • Autism irritability: 0.5 to 3 mg/day
  • Bipolar mania, 10 to 17 y/o: 1 to 6 mg/day; above that not studied
  • Schizophrenia, 13 to 17 y/o: 1 to 6 mg/day, no added benefit above 3 mg/day; above 6 mg/day not studied
  • Adults, schizophrenia: above 6 mg/day no more effective and more EPS; 16 mg/day highest studied
  • With fluoxetine or paroxetine: do not exceed 8 mg/day in adults
• Considerations: Give once daily, or split if somnolence persists; a bedtime dose is the usual answer to daytime sedation. Start 0.5 mg twice daily in severe renal or hepatic impairment.

Pharmacology

• Mechanism: D2 and 5-HT2A antagonist with alpha-1 and H1 blockade; alpha-1 drives orthostasis, H1 the sedation
• Delivery / Release: immediate-release; peak about 1 hour, unaffected by food
• Metabolism: CYP2D6 to paliperidone, similarly active; combined half-life about 20 hours
• Pharmacogenomics: no genotype-based dose adjustment; do not extrapolate the aripiprazole halving rule here
• Class Positioning: the label states risperidone gives higher prolactin elevations than other antipsychotics, persisting on chronic dosing; aripiprazole (Abilify) usually lowers prolactin
• That difference drives the choice between the two in a growing child

Indications

• Irritability Associated with Autistic Disorder (ICD-10: F84.0): 5 to 17 y/o. Labeled targets: aggression, self-injury, tantrums, quickly changing moods.
• Bipolar I Disorder, acute manic or mixed episodes (ICD-10: F31.x): 10 to 17 y/o and adults; adjunctive with lithium or valproate.
• Schizophrenia (ICD-10: F20.x): 13 to 17 y/o and adults

Off-Label Uses

• Aggression and conduct problems in ADHD and disruptive behaviour disorders (ICD-10: F90.x, F91.x): moderate strength of evidence; second line, after the primary disorder is treated. (AHRQ 2017; AACAP 2011)
• Tic disorders and Tourette's disorder (ICD-10: F95.2): low strength of evidence; aripiprazole holds the FDA indication here. (AHRQ 2017)
• Behavioural disturbance with intellectual disability (ICD-10: F70-F79): low strength of evidence. (AHRQ 2017)
• Obsessive-compulsive disorder augmentation (ICD-10: F42.x): insufficient. (AHRQ 2017)
• Core ADHD symptoms, anxiety, depression (ICD-10: F90.x, F41.x, F32.x): insufficient. Use Concerta, Strattera or Qelbree. (AHRQ 2017)

Contraindications & Warnings

• Boxed Warning: Increased mortality in elderly patients with dementia-related psychosis. Risperidone is not approved for that use.
• Contraindicated:
  • Known hypersensitivity to risperidone, to paliperidone (its active metabolite), or to any excipient.
• Use with caution:
  • Any condition predisposing to hypotension, or a concurrent antihypertensive.
  • Diabetes, obesity, dyslipidemia, or a family history of them.
  • A child or adolescent in puberty; persistent hyperprolactinemia with hypogonadism reduces bone density.
  • History of low white cell count, leukopenia, or neutropenia.
  • Seizure history, dysphagia, aspiration risk, and falls risk.
  • Severe renal impairment (CrCl under 30 mL/min) or Child-Pugh 10 to 15.
  • Conditions raising core temperature: exercise, heat, dehydration, anticholinergics.
• Screen before starting:
  • Weight, height, BMI percentile, waist circumference, standing blood pressure.
  • Fasting glucose or A1c, and a fasting lipid panel.
  • Family history of diabetes, dyslipidemia, obesity, cardiovascular disease.
  • AIMS, pubertal staging, menstrual history in an adolescent girl.

Drug Interactions

• Enzyme inducers (carbamazepine, phenytoin, rifampin, phenobarbital): levels fall. Increase up to double; reverse when the inducer stops.
• CYP2D6 inhibitors (fluoxetine, paroxetine, bupropion, quinidine): levels rise. Reduce the initial dose; do not exceed 8 mg/day in adults.
• Antihypertensives and hypotensive agents: additive orthostatic hypotension; check lying and standing blood pressure.
• CNS depressants, alcohol, sedating antihistamines: additive sedation; counsel adolescents explicitly.
• Anticholinergics: additive impairment of temperature regulation.
• Other prolactin-raising drugs (metoclopramide, antipsychotics): additive hyperprolactinemia.

Administration

• Give the total daily dose once daily or split; food does not affect absorption.
• Tablet: swallow whole. ODT: dissolve on the tongue; do not chew, crush, or push through the foil.
• Oral solution: use a dosing syringe; at 1 mg/mL a 0.25 mg dose is 0.25 mL.
• After an interruption, restart on the initial titration schedule.
• Do not stop abruptly; see Discontinuation & Taper.

Side Effects

• Common: sedation (63% in the pediatric autism trials), increased appetite, fatigue, vomiting, constipation, enuresis, drooling, headache, weight gain, tremor, parkinsonism
• Serious:
  • Neuroleptic malignant syndrome: fever, rigidity, altered mental status, autonomic instability.
  • Tardive dyskinesia: assess with AIMS; consider discontinuing.
  • Metabolic change: 32.6% of pediatric patients gained 7% or more of body weight, against 6.9% on placebo.
  • Hyperglycemia and diabetes: check glucose for polydipsia, polyuria or polyphagia.
  • Hyperprolactinemia, higher than other antipsychotics and persisting: galactorrhea, amenorrhea, gynecomastia, reduced bone density.
  • Orthostatic hypotension, syncope, falls.
  • Leukopenia, neutropenia, agranulocytosis: discontinue for an unexplained fall.
  • Seizures, dysphagia, priapism, impaired temperature regulation, cognitive and motor impairment.

Monitoring & Labs

• Weight and BMI: baseline, 4, 8 and 12 weeks after any start or dose change, then quarterly. Consider switching on a gain of 5% or more. (ADA 2004)
• Waist circumference: baseline, then annually. (ADA 2004)
• Fasting glucose or A1c: baseline, 12 weeks, then annually; sooner with weight gain or family history. (ADA 2004)
• Fasting lipid panel: baseline and 12 weeks, then every 5 years if normal. (ADA 2004)
• Blood pressure: baseline, 12 weeks, then annually, plus a standing reading at every dose change. (ADA 2004)
• AIMS: baseline, then every 3 months in children; ask about akathisia and stiffness during titration.
• Prolactin: baseline in an adolescent, and if symptomatic. Ask about galactorrhea, gynecomastia, amenorrhea and delayed puberty every 3 months.
• Growth and puberty: height and pubertal staging every 6 months; menstrual history every visit in an adolescent girl.
• Complete blood count: not routine; check with a low white cell history, fever or infection.

Discontinuation & Taper

• Taper gradually rather than stopping abruptly, to limit withdrawal dyskinesia and rebound. Guideline, not label. (AACAP 2011)
• Once response is maintained, the label directs a gradual dose reduction. Reassess the indication every 6 months. (AACAP 2011)
• Discontinue immediately for suspected neuroleptic malignant syndrome; consider it for tardive dyskinesia or an unexplained white cell fall.
• Prolactin normalises a median 4 to 6 weeks after stopping or switching. (LactMed 2026)

Pregnancy & Lactation

• Pregnancy: Third-trimester exposure risks neonatal extrapyramidal or withdrawal symptoms. No established risk of major birth defects; weigh continuation against maternal relapse.
• Lactation: Maternal doses up to 6 mg daily give low milk levels, but sedation, failure to thrive, tremor and respiratory depression are reported. (LactMed 2026)
• Lactation, agent choice: Reviews place risperidone second line while breastfeeding; monitor the infant for drowsiness, weight gain, tremor. (LactMed 2026)
• Exposure Registry: National Pregnancy Registry for Atypical Antipsychotics, 1-866-961-2388, womensmentalhealth.org

Counseling Points

• Counsel the family on:

  • Sleepiness in the first weeks, in two thirds of children; the fix is a bedtime dose.
  • Appetite increase and weight gain expected, with weight plotted every visit.
  • Breast tenderness or enlargement, milk production, or periods stopping; name these early.
  • The dose ladder being deliberately slow, so pauses are not read as inaction.
  • Caution with heat and sport; rise slowly from lying or sitting.

• Advise them to call for:

  • Fever with muscle stiffness or confusion, an emergency.
  • Involuntary movement of the face, tongue or limbs, or inability to sit still.
  • Milk from the breasts, breast swelling, or periods stopping.
  • Fainting, or dizziness on standing that does not settle.
  • Marked thirst, frequent urination, or unexplained weight loss.
  • Difficulty swallowing or choking.
  • An erection lasting more than 4 hours, an emergency.

References

1. DailyMed. Risperdal (risperidone) prescribing information. Janssen. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=7e117c7e-02fc-4343-92a1-230061dfc5e0
2. American Diabetes Association and others. Consensus conference on antipsychotic drugs, obesity and diabetes. Diabetes Care. 2004. https://diabetesjournals.org/care/article/27/2/596/28450/
3. AACAP. Practice parameter for atypical antipsychotics in children and adolescents. 2011. https://www.aacap.org/App_Themes/AACAP/docs/practice_parameters/Atypical_antipsychotic_Medications_Web.pdf
4. AHRQ. Antipsychotics in children and young adults. Comparative Effectiveness Review No. 184. 2017. https://www.ncbi.nlm.nih.gov/books/NBK442344/
5. LactMed. Risperidone. Drugs and Lactation Database, NICHD. 2026. https://www.ncbi.nlm.nih.gov/books/NBK501095/
6. FDA. National Drug Code Directory, openFDA. 2026. https://open.fda.gov/apis/drug/ndc/