Risperdal (risperidone) is an atypical antipsychotic medication indicated for the treatment of schizophrenia, bipolar disorder, and irritability associated with autistic disorder. It functions by modulating dopamine and serotonin activity in the brain, offering a balanced receptor profile that supports both efficacy and tolerability. Clinically validated across numerous randomized controlled trials, it remains a cornerstone in psychiatric pharmacotherapy for managing acute episodes and maintaining long-term stability.

Features

• Contains risperidone as the active pharmaceutical ingredient
• Available in multiple formulations: oral tablets, orally disintegrating tablets, and long-acting injectable (Risperdal Consta)
• Standard tablet strengths: 0.25 mg, 0.5 mg, 1 mg, 2 mg, 3 mg, 4 mg
• Bioavailability approximately 70% when administered orally
• Metabolized primarily via CYP2D6 hepatic pathway
• Half-life of approximately 20 hours in extensive metabolizers

Benefits

• Reduces positive and negative symptoms of schizophrenia, including hallucinations, delusions, and social withdrawal
• Stabilizes mood episodes in bipolar I disorder, decreasing frequency and severity of manic episodes
• Improves behavioral symptoms such as aggression, self-injury, and sudden mood changes in autistic disorder
• Lower risk of extrapyramidal symptoms compared to conventional antipsychotics
• Long-acting injectable formulation supports adherence and consistent plasma levels
• Evidence-based efficacy across diverse patient populations and age groups (where approved)

Common use

Risperdal is primarily prescribed for the management of schizophrenia in adults and adolescents aged 13 years and older. It is also approved for the acute treatment of manic or mixed episodes associated with bipolar I disorder in adults and pediatric patients aged 10 years and older. Additionally, it is indicated for the treatment of irritability—including aggression, self-injurious behavior, and temper outbursts—in children and adolescents aged 5 to 16 years with autistic disorder.

Dosage and direction

Dosage must be individualized based on clinical condition, patient response, and tolerability. For schizophrenia in adults: initiate at 2 mg/day, may increase to 4–8 mg/day. For bipolar mania in adults: start at 2–3 mg/day, adjust in increments of 1 mg/day. For irritability in autism: begin at 0.25 mg/day (for <20 kg) or 0.5 mg/day (for ≥20 kg). Titrate gradually. Tablets should be taken with or without food, once or twice daily. Long-acting injectable Risperdal Consta is administered every two weeks via intramuscular injection by a healthcare professional.

Precautions

Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Risperdal is not approved for use in patients with dementia-related psychosis. Monitor for neuroleptic malignant syndrome (NMS), tardive dyskinesia (TD), metabolic changes (weight gain, hyperglycemia, dyslipidemia), orthostatic hypotension, and seizures. Use caution in patients with cardiovascular disease, Parkinson’s disease, or renal/hepatic impairment. Regular assessments of BMI, blood glucose, and lipid profiles are recommended.

Contraindications

Hypersensitivity to risperidone or any component of the formulation. Concomitant use with drugs that prolong QT interval in patients with known QT prolongation or cardiac arrhythmia. Severe renal or hepatic impairment may require dose adjustment or avoidance.

Possible side effect

Common adverse reactions (≥5%) include: somnolence, dizziness, akathisia, nausea, constipation, weight gain, insomnia, and hyperprolactinemia. Less frequently: extrapyramidal symptoms, tachycardia, orthostatic hypotension, fatigue, anxiety, blurred vision. Rare but serious: neuroleptic malignant syndrome, tardive dyskinesia, seizures, diabetic ketoacidosis, priapism, cerebrovascular events in elderly patients with dementia.

Drug interaction

Strong CYP2D6 inhibitors (e.g., fluoxetine, paroxetine) may increase risperidone concentrations. Carbamazepine and other CYP3A4 inducers may decrease concentrations. Avoid concomitant use with other CNS depressants. Caution with antihypertensives (additive hypotension), levodopa/dopamine agonists (antagonistic effects), and drugs that prolong QT interval (e.g., quinidine, amiodarone).

Missed dose

If a dose is missed, take it as soon as remembered unless it is close to the time of the next dose. Do not double the dose to make up for a missed one. For the long-acting injectable form, contact the healthcare provider to reschedule administration.

Overdose

Symptoms may include drowsiness, sedation, tachycardia, hypotension, extrapyramidal symptoms, and QT prolongation. Provide supportive care: maintain airway, ensure adequate oxygenation, monitor cardiac function. There is no specific antidote. Activated charcoal may be considered if ingestion was recent. Hemodialysis is not expected to be effective.

Storage

Store at controlled room temperature (20–25°C/68–77°F). Protect from light and moisture. Keep out of reach of children and pets. Do not use after the expiration date printed on the packaging.

Disclaimer

This information is intended for educational purposes and does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting, changing, or discontinuing any medication. Individual patient responses may vary.

Reviews

Risperdal has been extensively studied in clinical trials and real-world settings. Meta-analyses and systematic reviews consistently support its efficacy in reducing psychotic and manic symptoms, with a generally acceptable safety profile. Many clinicians appreciate its versatility and the option of a long-acting formulation for non-adherent patients. Some criticisms include its metabolic side effects and risk of hyperprolactinemia. Overall, it remains a widely used and respected agent in psychiatric practice.