Risperidone (sold as Risperdal) was the second second-generation antipsychotic to reach widespread use after clozapine, approved by the FDA in 1993. It quickly became one of the most prescribed antipsychotics worldwide. Today it remains a workhorse of treatment for schizophrenia and several other conditions.
Risperidone is an effective, generally well-tolerated antipsychotic at low to moderate doses, with the advantage of a long-acting injectable formulation for patients who need consistent dosing.
How it works
Risperidone is a strong serotonin 5-HT2A and dopamine D2 receptor antagonist. The serotonin blockade gives it the "atypical" profile — meaning fewer extrapyramidal side effects than older antipsychotics, particularly at low doses. At higher doses (above ~6 mg/day), the dopamine blockade dominates and the side effect profile starts to look more like a first-generation antipsychotic.
What it treats
- Schizophrenia in adults and children 13+
- Bipolar I disorder — acute manic or mixed episodes
- Irritability associated with autistic disorder in children 5–16
- Off-label uses include severe agitation, OCD augmentation, behavioural disturbances in dementia (with caution due to FDA black box warning for elderly dementia patients)
Dosing
- Schizophrenia (adults): usually 2–8 mg/day, split into 1–2 doses
- Bipolar mania: 1–6 mg/day
- Children/adolescents: 0.5–6 mg/day depending on indication and weight
Doses above 6 mg/day rarely add antipsychotic benefit but substantially increase movement-related side effects.
The long-acting injectable
Risperidone is available as a long-acting injection (Risperdal Consta) given every 2 weeks. Its newer cousin, paliperidone palmitate, is the active metabolite of risperidone and is available as monthly (Invega Sustenna), every-3-month (Invega Trinza), and every-6-month (Invega Hafyera) injections. Long-acting formulations dramatically reduce the risk of relapse caused by missed doses and are increasingly considered first-line for many patients with schizophrenia.
How effective it is
In meta-analyses, risperidone consistently ranks in the upper-middle of antipsychotic effectiveness — generally similar to other second-generation drugs like paliperidone and haloperidol, less effective on average than clozapine and olanzapine for severe symptoms, but with a better tolerability profile than clozapine and (at low to moderate doses) better metabolic profile than olanzapine.
Side effects to know about
Extrapyramidal symptoms (EPS)
Movement-related side effects (stiffness, restlessness, tremor) increase with dose, especially above 6 mg/day. At lower doses they are generally mild.
Hyperprolactinaemia
Risperidone is one of the most prolactin-elevating antipsychotics. High prolactin can cause:
- Sexual side effects (low libido, erectile difficulty)
- Menstrual irregularities or absence in women
- Galactorrhea (milk discharge from breasts) in either sex
- Long-term effects on bone density
Prolactin should be checked at baseline and if symptoms develop. A switch to a more prolactin-sparing antipsychotic (aripiprazole, ziprasidone) often resolves this.
Weight gain and metabolic effects
Less than olanzapine or clozapine but still significant — average 2–3 kg in the first year, plus modest effects on glucose and lipids.
Sedation
Less than olanzapine but more than aripiprazole. Often improves over weeks.
Orthostatic hypotension
Common during dose titration. Usually resolves.
Tardive dyskinesia
Like all dopamine-blocking medications, risperidone carries a long-term risk of tardive dyskinesia — involuntary movements that may persist after stopping the medication. Risk is lower than with first-generation antipsychotics but real, particularly at higher doses or in older patients.
Who it's a good fit for
- Patients with first-episode psychosis (often well tolerated at low doses)
- Patients who need a long-acting injectable
- Patients who have responded to it before
- Patients who can't tolerate sedation or weight gain of olanzapine
Who might want to consider alternatives
- Patients with prolactin-related side effects (consider aripiprazole)
- Patients with significant movement-related side effects on risperidone (consider lurasidone, aripiprazole)
- Patients with severe weight gain on risperidone
Discontinuation
Risperidone should be tapered, not stopped abruptly. Sudden discontinuation can cause withdrawal symptoms and risk of psychotic relapse.
This article is for educational purposes only and is not medical advice. Information is summarised from publicly available FDA labelling. Always consult your prescribing clinician before starting, stopping, or changing any medication.