Risperidone

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.

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