Risperidone
Risperidone is an atypical antipsychotic used to treat schizophrenia, bipolar disorder, and irritability associated with autism. It works by affecting dopamine and serotonin in the brain.
About Risperidone
Risperidone is a second-generation (atypical) antipsychotic — benzisoxazole derivative also sold under brand names including Risperdal and Risperdal Consta. It is primarily used to is prescribed to treat: • Schizophrenia in adults and adolescents (13+) • Bipolar I disorder (acute manic or mixed episodes) • Irritability associated with autistic disorder in children (5 16 years) • Major depressive disorder (adjunctive treatment off label) It helps reduce hallucinations, delusions, and mood symptoms. Risperidone is available in oral tablet (0.25 mg, 0.5 mg, 1 mg, 2 mg, 3 mg, 4 mg), orally disintegrating tablet — m-tab (0.5 mg, 1 mg, 2 mg, 3 mg, 4 mg), oral solution (1 mg/ml), long-acting im injection — risperdal consta (12.5 mg, 25 mg, 37.5 mg, 50 mg every 2 weeks), and long-acting sc injection — perseris (90 mg, 120 mg monthly) form. Healthcare providers commonly prescribe Risperidone for conditions including Atrial Fibrillation, Bipolar Disorder, Mixed Hyperlipidemia, and Seizures.
Risperidone at a Glance
- Brand names
- Risperdal, Risperdal Consta
- Drug class
- Second-Generation (Atypical) Antipsychotic — Benzisoxazole Derivative
- Pregnancy category
- FDA Category Category C — Animal studies have shown adverse effects; controlled human data are limited. Third-trimester exposure can cause neonatal extrapyramidal symptoms or withdrawal (agitation, hypertonia, feeding problems). Untreated psychotic illness in pregnancy also carries significant risk; the decision to continue should be individualized.
- Available forms
- Oral tablet (0.25 mg, 0.5 mg, 1 mg, 2 mg, 3 mg, 4 mg), Orally disintegrating tablet — M-Tab (0.5 mg, 1 mg, 2 mg, 3 mg, 4 mg), Oral solution (1 mg/mL), Long-acting IM injection — Risperdal Consta (12.5 mg, 25 mg, 37.5 mg, 50 mg every 2 weeks), Long-acting SC injection — Perseris (90 mg, 120 mg monthly)
- Therapeutic categories
- Psychiatry, Antipsychotics, Bipolar Disorder, Schizophrenia
- Conditions treated
- 6 related conditions on this site
What Risperidone Is Used For
is prescribed to treat:
• Schizophrenia in adults and adolescents (13+) • Bipolar I disorder (acute manic or mixed episodes) • Irritability associated with autistic disorder in children (5-16 years) • Major depressive disorder (adjunctive treatment - off-label)
It helps reduce hallucinations, delusions, and mood symptoms.
Dosage Quick Reference
These are general dosage guidelines for Risperidone. Your doctor will determine the appropriate dose for your specific situation.
| Condition | Starting Dose | Maintenance Dose |
|---|---|---|
| Schizophrenia (adults) | 2 mg/day (single or divided) | 4–8 mg/day; max 16 mg/day (most patients respond at 4–6 mg) |
| Schizophrenia (adolescents 13–17) | 0.5 mg once daily | 3 mg once daily (range 1–6 mg/day) |
| Bipolar I mania (adults) | 2–3 mg once daily | 1–6 mg/day; max 6 mg/day |
| Bipolar I mania (children 10–17) | 0.5 mg once daily | 1–2.5 mg once daily (range 0.5–6 mg) |
| Irritability with autism (children 5–16) | 0.25 mg/day if < 20 kg; 0.5 mg/day if ≥ 20 kg | Titrate to 0.5–3 mg/day based on response and weight |
Side Effects
Common side effects may include:
• Weight gain • Drowsiness or sedation • Increased appetite • Fatigue • Dizziness • Dry mouth • Constipation • Tremor • Restlessness
Serious side effects (seek immediate medical attention):
• Neuroleptic malignant syndrome (high fever, muscle rigidity) • Tardive dyskinesia (uncontrollable movements) • Severe allergic reactions • Stroke (in elderly with dementia) • Metabolic changes (high blood sugar, diabetes) • Prolonged QT interval • Orthostatic hypotension • Seizures.com/what-is-epilepsy/seizure-types)
See also: Drug Interactions ↓
Drug Interactions
Risperidone is metabolized primarily by CYP2D6 to its active metabolite paliperidone, and major interactions involve CYP modulators, additive CNS effects, and cardiovascular concerns.
- CYP2D6 inhibitors (e.g., fluoxetine, paroxetine, bupropion, quinidine): Substantially increase risperidone plasma levels and the risk of extrapyramidal symptoms, sedation, and orthostatic hypotension. Consider lower risperidone doses.
- CYP3A4 inducers (e.g., carbamazepine, phenytoin, rifampin, St. John's wort): Decrease risperidone exposure and may reduce efficacy. Carbamazepine in particular can lower risperidone levels by roughly 50 percent; dose adjustments may be required.
- Antihypertensive agents (e.g., ACE inhibitors, ARBs, alpha-blockers, diuretics): Risperidone has alpha-1 adrenergic blocking activity and can cause orthostatic hypotension, especially during dose titration. Monitor blood pressure and counsel patients to rise slowly.
- CNS depressants (e.g., opioids, benzodiazepines, alcohol, sedating antihistamines): Additive sedation and respiratory depression. Use cautiously and counsel patients to avoid alcohol.
- QT-prolonging drugs (e.g., methadone, ondansetron, certain antiarrhythmics): Risperidone can modestly prolong QT. Combinations should be used cautiously, particularly in patients with electrolyte abnormalities or pre-existing cardiac disease.
- Dopaminergic agents (e.g., levodopa, dopamine agonists): Risperidone antagonizes dopamine receptors and can blunt the efficacy of Parkinson disease therapies; combinations should be avoided when possible.
See also: Questions to Ask Your Doctor ↓
Key Considerations
Known drug interactions
Risperidone has documented interactions with other medications, supplements, and certain foods. Review the Drug Interactions section below and tell your healthcare provider about every medication you take, including over-the-counter products. Jump to section →
Multiple forms available
Risperidone comes in more than one form (Oral tablet (0.25 mg, 0.5 mg, 1 mg, 2 mg, 3 mg, 4 mg), Orally disintegrating tablet — M-Tab (0.5 mg, 1 mg, 2 mg, 3 mg, 4 mg), Oral solution (1 mg/mL), Long-acting IM injection — Risperdal Consta (12.5 mg, 25 mg, 37.5 mg, 50 mg every 2 weeks), Long-acting SC injection — Perseris (90 mg, 120 mg monthly)). The right form for you depends on your condition, ease of use, and your provider's recommendation.
Additional Information
What is ?
Risperidone is a second-generation (atypical) antipsychotic medication used to treat various psychiatric conditions. It's one of the most commonly prescribed antipsychotics worldwide.
How Does Risperidone Work?
Risperidone affects multiple neurotransmitter systems:
- Blocks dopamine D2 receptors (antipsychotic effect)
- Blocks serotonin 5-HT2A receptors
- Moderate alpha-1 adrenergic blockade
- Helps regulate mood and thought processes
- Reduces positive and negative symptoms of psychosis
Common Uses
- Schizophrenia: Treats positive and negative symptoms
- Bipolar Mania: Acute treatment of manic episodes
- Autism-Related Irritability: Reduces aggression, self-injury, tantrums
- Major Depression: Adjunctive treatment (off-label)
- OCD: Augmentation strategy (off-label)
Dosage Forms
Oral:
- Tablets: 0.25, 0.5, 1, 2, 3, 4 mg
- Oral solution: 1 mg/mL
- Orally disintegrating tablets (M-TAB)
Injectable:
- Risperdal Consta: Long-acting injection (every 2 weeks)
Dosage and Administration
Schizophrenia (Adults):
- Initial: 2 mg/day (divided or once daily)
- Target: 4-8 mg/day
- Maximum: 16 mg/day
Schizophrenia (Adolescents 13-17):
- Initial: 0.5 mg once daily
- Increase by 0.5-1 mg/day
- Target: 3 mg/day
- Maximum: 6 mg/day
Bipolar Mania:
- Initial: 2-3 mg once daily
- Adjust by 1 mg/day
- Target: 1-6 mg/day
Autism-Related Irritability (Children 5-16):
- Weight <20 kg: Start 0.25 mg/day
- Weight ≥20 kg: Start 0.5 mg/day
- Increase gradually based on response
Administration Tips:
- Can take with or without food
- Take at same time each day
- Orally disintegrating tablet: place on tongue, dissolves rapidly
- Solution: measure with provided calibrated syringe
Important Safety Information
Black Box Warnings
⚠️ ELDERLY WITH DEMENTIA-RELATED PSYCHOSIS:
- Increased risk of death
- Most deaths appeared cardiovascular or infectious
- Not approved for dementia-related psychosis
⚠️ SUICIDAL THOUGHTS AND BEHAVIORS:
- Increased risk in children, adolescents, young adults
- Monitor closely especially early in treatment
- Family should watch for worsening mood, unusual behavior
Neuroleptic Malignant Syndrome (NMS)
Rare but potentially fatal:
- High fever
- Muscle rigidity
- Altered mental status
- Autonomic instability
- Elevated CPK
Action: Stop medication immediately and seek emergency care
Tardive Dyskinesia (TD)
Potentially irreversible:
- Involuntary movements of face, tongue, limbs
- Risk increases with longer treatment and higher doses
- Higher risk in elderly, especially women
- Monitor for abnormal movements
- Consider discontinuing if TD develops
Metabolic Changes
Monitor closely:
Weight Gain:
- Average 5-15 lb gain
- More common in children and adolescents
- Monitor weight regularly
Hyperglycemia and Diabetes:
- Can cause or worsen diabetes
- Monitor blood glucose regularly
- Watch for symptoms: increased thirst, urination, hunger
- May need diabetes medication adjustment
Dyslipidemia:
- Increased cholesterol and triglycerides
- Monitor lipid panel regularly
Metabolic Syndrome:
- Combination of weight gain, high blood sugar, high lipids, high BP
- Increases cardiovascular risk
Hyperprolactinemia
Elevated prolactin levels:
- More common than with other atypicals
- Women: irregular periods, galactorrhea, sexual dysfunction
- Men: gynecomastia, erectile dysfunction, decreased libido
- Long-term: potential bone density loss
- Monitor if symptomatic
Orthostatic Hypotension
Blood pressure drops when standing:
- Can cause dizziness, fainting
- Higher risk when starting or increasing dose
- Rise slowly from sitting or lying
- Stay hydrated
- Higher risk in elderly
QT Prolongation
- Can prolong QT interval on ECG
- Risk of serious arrhythmias
- Use caution with:
- Heart disease
- Family history of sudden death
- Electrolyte imbalances
- Other QT-prolonging drugs
Seizures
- May lower seizure threshold
- Use caution in patients with seizure history
- More likely at higher doses
Who Should Not Take Risperidone?
- Hypersensitivity to risperidone or paliperidone
- Use caution in elderly with dementia
Drug Interactions
CYP2D6 Interactions:
- Fluoxetine, paroxetine (increase risperidone levels)
- Carbamazepine (decreases risperidone levels)
CNS Depressants:
- Alcohol, benzodiazepines, opioids
- Increased sedation and respiratory depression
Antihypertensives:
- Enhanced blood pressure lowering
Dopamine Agonists:
- Levodopa (may reduce effectiveness of both)
QT-Prolonging Drugs:
- Increased arrhythmia risk
Monitoring
Baseline:
- Weight, BMI, waist circumference
- Blood pressure
- Fasting glucose and lipid panel
- Complete blood count
- Liver function tests
- ECG if cardiac risk factors
- Abnormal Involuntary Movement Scale (AIMS)
Regular Monitoring:
- Weight and BMI: every visit initially, then quarterly
- Blood pressure and pulse: each visit
- Fasting glucose: 3 months, then annually
- Lipid panel: 3 months, then annually
- Monitor for movement disorders
- Prolactin if symptomatic
- ECG if indicated
Managing Side Effects
Weight Gain:
- Nutritional counseling
- Exercise program
- Consider switching to alternative if significant
- Metformin may help (off-label)
Sedation:
- Take at bedtime
- May decrease over time
- Consider dose reduction
Orthostatic Hypotension:
- Rise slowly
- Stay hydrated
- Compression stockings
- May need dose reduction
Sexual Side Effects:
- Check prolactin level
- Dose reduction may help
- Consider alternative medication
Pregnancy and Breastfeeding
Pregnancy:
- Category C (previously)
- Crosses placenta
- Use only if benefit outweighs risk
- Third-trimester exposure may cause withdrawal or extrapyramidal symptoms in newborn
Breastfeeding:
- Excreted in breast milk
- Weigh risks vs. benefits
- Monitor infant closely if breastfeeding
Discontinuation
Taper gradually:
- Abrupt discontinuation may cause withdrawal
- Symptoms: nausea, vomiting, insomnia, agitation
- Taper over weeks to months
- Monitor for symptom recurrence
Special Populations
Children and Adolescents:
- Higher risk of metabolic side effects
- More weight gain than adults
- Monitor growth and development
- Consider non-pharmacological interventions first
Elderly:
- Start with lower doses (0.25-0.5 mg twice daily)
- Increased fall risk
- Higher risk of stroke, death (dementia patients)
- Monitor closely for side effects
Kidney Disease:
- Lower doses recommended
- Monitor closely
Liver Disease:
- Use caution
- Consider dose reduction
Response to Treatment
Timeline:
- Acute agitation: within hours to days
- Psychotic symptoms: 1-2 weeks for initial response
- Full benefit: 4-6 weeks
- Negative symptoms: may take longer
Long-Acting Injectable (Risperdal Consta)
Advantages:
- Ensures medication adherence
- Steady blood levels
- Given every 2 weeks
- Reduces relapse rates
Considerations:
- Must first establish tolerance to oral form
- Continue oral for 3 weeks after first injection
- Administered by healthcare professional
When to Contact Your Doctor Immediately
- High fever with muscle stiffness
- Uncontrollable movements
- Confusion or altered consciousness
- Rapid or irregular heartbeat
- Severe dizziness or fainting
- Difficulty swallowing or breathing
- Prolonged or painful erection (rare)
- Signs of high blood sugar
- Suicidal thoughts
- Severe allergic reaction
When to Call During Office Hours
- Significant weight gain
- New or worsening depression
- Tremors or restlessness
- Sexual side effects
- Irregular periods or breast discharge
- Excessive sedation
- Difficulty with movements
Frequently Asked Questions
Questions to Ask Your Doctor About Risperidone
Consider discussing these topics at your next appointment:
- How will we monitor for side effects like weight gain, blood sugar changes, and movement problems?
- Would a long-acting injectable form be a better fit than a daily pill for my situation?
- What symptoms or warning signs should prompt me to contact you between visits?
- How long do you anticipate I will need to stay on risperidone?
- Are there alternatives with a lower risk of prolactin elevation or metabolic side effects?
Medical Disclaimer: This information is for educational purposes only and should not be considered medical advice. Always consult with your healthcare provider before starting, stopping, or changing any medication. Your doctor can provide personalized recommendations based on your specific health condition and medical history.