Atypical Antipsychotic — Autism Spectrum Disorder / Schizophrenia / Tic Disorders Pregnancy: 'Risperidone should not be used during pregnancy unless clearly necessary. If discontinuation during pregnancy is necessary, it should not be done abruptly.' There are no adequate data in pregnant women; risperidone was not teratogenic in animal studies but other types of reproductive toxicity were seen, and the potential risk for humans is unknown. Neonates exposed to antipsychotics during the third trimester are at risk of extrapyramidal and/or withdrawal symptoms varying in severity and duration after delivery (agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress, feeding disorder) — newborns should be monitored carefully (§4.6).

Risperidone (Paediatric)

Brand names: Risperdal, Risperidone Orodispersible

Risperidone is a second-generation antipsychotic used in children most often for short-term treatment of persistent aggression in conduct disorder and irritability associated with autism, and in some adolescent psychotic and bipolar presentations.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Schizophrenia: start at 2 mg/day; the dosage may be increased on the second day to 4 mg; most patients benefit from daily doses between 4 and 6 mg. Manic episodes in bipolar disorder: start at 2 mg once daily, with adjustments of 1 mg per day at intervals of not less than 24 hours, over a flexible range of 1 to 6 mg per day

Route: Oral — food does not affect the absorption of risperidone

Frequency: Schizophrenia: once daily or twice daily. Bipolar mania: once daily

Max: Schizophrenia — 'Doses above 10 mg/day have not demonstrated superior efficacy to lower doses and may cause increased incidence of extrapyramidal symptoms. Safety of doses above 16 mg/day has not been evaluated, and are therefore not recommended.' Bipolar mania — 'Daily doses over 6 mg risperidone have not been investigated in patients with manic episodes'

SOURCE: eMC UK SPC, productName 'Risperidone 0.5mg Film-Coated Tablets', §4.2. PAEDIATRIC RESTRICTIONS — VERBATIM: 'Risperidone is not recommended for use in children below age 18 with schizophrenia due to a lack of data on efficacy' and 'Risperidone is not recommended for use in children below age 18 with bipolar mania due to a lack of data on efficacy.' CONDUCT DISORDER is the only paediatric indication in this SPC and its doses are FIXED mg doses by weight band, not per-kg, which is why paedDose is null — VERBATIM §4.2, children and adolescents from 5 to 18 years of age: 'For subjects >= 50 kg, a starting dose of 0.5 mg once daily is recommended. This dosage can be individually adjusted by increments of 0.5 mg once daily not more frequently than every other day, if needed. The optimum dose is 1 mg once daily for most patients. Some patients, however, may benefit from 0.5 mg once daily while others may require 1.5 mg once daily. For subjects <50 kg, a starting dose of 0.25 mg once daily is recommended. This dosage can be individually adjusted by increments of 0.25 mg once daily not more frequently than every other day, if needed. The optimum dose is 0.5 mg once daily for most patients. Some patients, however, may benefit from 0.25 mg once daily while others may require 0.75 mg once daily.' 'Risperidone is not recommended in children less than 5 years of age, as there is no experience in children less than 5 years of age with this disorder.' Continued use must be evaluated and justified on an ongoing basis. ELDERLY (schizophrenia and bipolar mania): a starting dose of 0.5 mg twice daily is recommended, individually adjusted with 0.5 mg twice-daily increments to 1 to 2 mg twice daily. PERSISTENT AGGRESSION IN MODERATE TO SEVERE ALZHEIMER'S DEMENTIA: start 0.25 mg twice daily, adjusted by increments of 0.25 mg twice daily no more frequently than every other day; the optimum dose is 0.5 mg twice daily for most patients, and some may benefit from up to 1 mg twice daily — should not be used for more than 6 weeks. DISCONTINUATION: gradual withdrawal is advised. Source §4.4 and §4.8 were truncated at the source-fetch limit and §4.5 was not retrieved. Verify all under-18 dosing against a children's formulary.

Dose adjustments

Renal

'Patients with renal impairment have less ability to eliminate the active antipsychotic fraction than in adults with normal renal function. Patients with impaired hepatic function have increases in plasma concentration of the free fraction of risperidone. Irrespective of the indication, starting and consecutive dosing should be halved, and dose titration should be slower for patients with renal or hepatic impairment. Risperidone should be used with caution in these groups of patients' (§4.2).

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substance or to any of the excipients

Side effects

Parkinsonism (very common, incidence 10% or more; dose-related)
Sedation/somnolence (very common)
Headache (very common)
Insomnia (very common)
Akathisia (dose-related); hyperprolactinaemia; weight increased and increased appetite; neutropenia, decreased white blood cell count and thrombocytopenia

Interactions

Carbamazepine and other enzyme inducers — decrease plasma concentrations of risperidone; the US label advises increasing the risperidone dose up to double the patient's usual dose, titrating slowly (US label §7.1)
Fluoxetine, paroxetine and other CYP2D6 enzyme inhibitors — increase plasma concentrations of risperidone; reduce the initial dose and do not exceed a final dose of 8 mg per day (US label §7.1)
Ranitidine, cimetidine, amitriptyline and erythromycin — dose adjustment is not recommended when co-administered (US label §7.1)
NOTE: the UK SPC §4.5 interaction section was NOT retrieved in this source bundle — the interactions above are taken from the US label and must be verified against the UK SPC

Clinical monograph

How it works

It antagonises dopamine D2 and serotonin 5-HT2A receptors, modulating dopaminergic and serotonergic transmission implicated in psychosis, mood and behaviour.

Prescribing in practice

Metabolic effects (weight gain, dyslipidaemia, hyperglycaemia) and marked hyperprolactinaemia are prominent in children and can affect growth and puberty, so weight, growth and metabolic parameters must be tracked and treatment kept to the shortest effective course.
Extrapyramidal symptoms, sedation and rarely neuroleptic malignant syndrome can occur, and QT prolongation risk warrants caution with other QT-prolonging drugs.
Doses are low and titrated by weight and age; confirm against a children's formulary.

Monitoring

Baseline and periodic monitoring of weight and height, BMI, blood glucose, lipids and prolactin is required, alongside review for extrapyramidal and movement effects.

Counselling the patient

Report rapid weight gain, breast changes or milk production, or abnormal movements.
Be aware it can cause drowsiness, especially when starting.
Do not stop abruptly; treatment should be reviewed regularly for continued need.

Evidence & guidelines

Risperidone is recommended in NICE guidance for short-term management of severe persistent aggression in conduct disorder and is used for autism-associated irritability with close metabolic monitoring.

Reference: NICE NG11 (ASD); RUPP Trial NEJM 2002; MHRA Antipsychotic Metabolic Monitoring Guidelines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways