Atypical Antipsychotic (D2/5-HT2A Antagonist) Pregnancy: Not to be used during pregnancy unless clearly necessary; neonates exposed during the third trimester may develop extrapyramidal and/or withdrawal symptoms — monitor newborns. Do not discontinue abruptly. Excreted in breast milk in small quantities — weigh benefit of breast-feeding against risk.

Risperidone

Brand names: Risperdal, Risperdal Consta (LAI)

Risperidone is a second-generation (atypical) antipsychotic used for schizophrenia, acute mania in bipolar disorder, and short-term treatment of persistent aggression in certain situations.

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 (adults): start 2 mg/day; may increase to 4 mg on day 2; most patients benefit from 4–6 mg/day

Route: Oral

Frequency: Once or twice daily

Max: 16 mg/day (safety above 16 mg/day not evaluated; doses above 10 mg/day show no superior efficacy and increase extrapyramidal symptoms)

Manic episodes in bipolar disorder (adults): once daily, start 2 mg; adjust by 1 mg/day at intervals of not less than 24 h; flexible range 1–6 mg/day (doses above 6 mg/day not investigated). Persistent aggression in moderate-to-severe Alzheimer's dementia: start 0.25 mg twice daily; titrate by 0.25 mg twice daily no more often than every other day; optimum 0.5 mg twice daily for most (up to 1 mg twice daily); use no longer than 6 weeks. Elderly: start 0.5 mg twice daily, titrate by 0.5 mg twice daily to 1–2 mg twice daily. Renal or hepatic impairment: halve starting and subsequent doses and titrate more slowly. Food does not affect absorption; gradual withdrawal advised on discontinuation. Paediatric (conduct disorder, ages 5–18, eMC): dosed by body-weight band — ≥50 kg start 0.5 mg once daily (optimum 1 mg/day), <50 kg start 0.25 mg once daily (optimum 0.5 mg/day); this is a weight-banded fixed dose, not a per-kg dose. Not recommended under 18 years for schizophrenia or bipolar mania (lack of efficacy data). Verify paediatric use against a current children's formulary.

Dose adjustments

Renal

Renal (or hepatic) impairment: halve starting and subsequent doses and titrate more slowly (§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 risperidone (or paliperidone) or to any excipient

Side effects

Parkinsonism
Sedation/somnolence
Headache
Insomnia
Akathisia

Interactions

Carbamazepine and other enzyme inducers decrease plasma risperidone — may need up to double the usual dose; titrate slowly
Fluoxetine, paroxetine and other CYP2D6 inhibitors increase plasma risperidone — reduce the dose and do not exceed 8 mg/day
No dose adjustment needed with ranitidine, cimetidine, amitriptyline or erythromycin

Clinical monograph

How it works

It is a potent antagonist at dopamine D2 and serotonin 5-HT2A receptors, with additional alpha-adrenergic and histaminergic blockade, reducing positive psychotic symptoms while raising prolactin.

Prescribing in practice

It increases the risk of stroke and death when used for behavioural and psychological symptoms in elderly people with dementia, so such use must be short-term, justified and reviewed.
It commonly raises prolactin, which can cause galactorrhoea, sexual dysfunction and menstrual disturbance, and is dose-dependently associated with extrapyramidal side effects.
Postural hypotension can occur on initiation and dose titration, particularly in the elderly.

Monitoring

Monitor weight, fasting glucose or HbA1c, lipids, blood pressure, prolactin-related symptoms and emergence of extrapyramidal effects at baseline and regularly.

Counselling the patient

Report breast changes, milk production, sexual or menstrual problems, or muscle stiffness and abnormal movements.
Stand up slowly when starting treatment to reduce dizziness.
Attend regular physical-health checks and do not stop the medicine abruptly without advice.

Evidence & guidelines

NICE lists risperidone among first-line antipsychotic options for schizophrenia and bipolar mania, with explicit caution about stroke risk in dementia.

Reference: NICE NG117; BAP Antipsychotic 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