Risperidone

Antipsychotic Drug

Drug class: Atypical antipsychotic

Risperidone (RISPERDAL)（中文：利培酮）

Pronunciation

Risperidone 1mg

Risperidone 2mg

Risperidone orodispersible 1mg

Risperidone orodispersible 2mg

Common Strengths of Risperidone Tablet

Risperidone tablets are available in the following strengths:

• 0.25 mg, 0.5 mg, 1 mg, 2 mg, 3 mg, 4 mg tablets; 1 mg/mL oral solution

Drug Trade Names of Risperidone Tablet

Risperdal, Risperdal Consta (long-acting injectable form)

Drug Usage

Risperidone is used for:

• Treatment of schizophrenia
• Acute treatment of manic or mixed episodes associated with bipolar disorder
• Treatment of irritability associated with autistic disorder

Mechanism of Action

Risperidone is a selective monoaminergic antagonist with high affinity for serotonin 5-HT2 and dopamine D2 receptors

Route of Administration

• Oral (tablets and oral solution)
• Intramuscular injection (long-acting injectable form)

Dosages

• Schizophrenia (adults): Initial dose 2 mg/day, target dose 4 to 8 mg/day
• Bipolar mania (adults): Initial dose 2 to 3 mg/day, target dose 1 to 6 mg/day

For moderate to severe renal impairment (eGFR < 60 mL/min/1.73 m2):

• The maximum recommended dosage for schizophrenia is 3 mg per day.
• The maximum recommended dosage for major depressive disorder is 2 mg per day.

For patients with severe renal impairment (CrCl < 30 mL/min):

• Initial dose: 0.5 mg twice daily
• Titrate in increments of up to 0.5 mg twice daily
• Increases above 1.5 mg twice daily should occur at intervals of at least one week

Side Effects

Frequency	Adverse reactions
Common	Drowsiness
	Dizziness: which can increase the risk of falling
	Weight Gain: Increased appetite leading to weight gain
	Nausea: Feeling sick to the stomach
	Constipation
	Nausea
	Constipation
	Dry Mouth: Reduced saliva production
	Increased Saliva: Excessive saliva production
	Anxiety: Feelings of nervousness or worry
	Agitation: Restlessness or irritability
	Difficulty Sleeping: Trouble falling or staying asleep
	Blurred Vision: Changes in vision clarity
	Runny or Stuffy Nose: Cold-like symptoms
	Fatigue: General feeling of tiredness
Uncommon	Neuroleptic Malignant Syndrome (NMS): Symptoms include high fever, muscle stiffness, and altered mental status
	Tardive Dyskinesia**: Involuntary, repetitive movements, particularly of the face and limbs, which may be irreversible
	Metabolic Changes: Increased blood sugar, cholesterol and triglycerides, and weight gain, which can lead to diabetes
	Cognitive Impairment: Difficulty thinking or concentrating
	Heat Intolerance: Difficulty regulating body temperature, leading to overheating or hypothermia
	Increased Risk of Falls: Particularly in elderly patients due to dizziness and drowsiness
	Orthostatic Hypotension: Sudden drop in blood pressure upon standing, leading to dizziness or fainting
	Seizures: Convulsions or fits
	Low White Blood Cell Count: Increased risk of infections
	Allergic Reactions: Symptoms include rash, itching, and trouble breathing
	Stroke: Increased risk in elderly patients with dementia-related psychosis
	Increased Prolactin Levels: This can lead to breast milk production, menstrual irregularities, and sexual dysfunction

Pharmacokinetics

• Absorption
  • Peak plasma concentrations occurring within 1 to 2 hours
• Metabolism
  • Extensively metabolized in the liver by CYP2D6
• Elimination
  • Approximately 70% excreted in urine and 14% in feces. The half-life of the active moiety (risperidone plus 9-hydroxyrisperidone) is approximately 20 hours.

Drug onset time and duration: Onset of action may be seen within 1 to 2 weeks, with full effects typically observed within 4-6 weeks.

Drug Precautions

Increased risk in elderly patients

• Should not be used to treat dementia-related psychosis in older adults due to increased risk of stroke and death
• May cause drowsiness, dizziness, and difficulty swallowing in elderly patients, increasing the risk of falls and choking

Pregnancy

• Use with caution; potential risks to the fetus should be considered

Breastfeeding

• Not recommended; risperidone is excreted in human milk

Monitoring Requirements

• Weight, blood glucose, lipid profile, prolactin levels, signs of extrapyramidal symptoms

Drug Interactions

• May enhance the effects of other CNS depressants; caution with drugs that prolong QT interval as risperidone may cause QT prolongation

FAQ

How Should I Take the Tablet?

• Take risperidone exactly as prescribed by your doctor, usually once or twice daily with or without food.

What should I avoid while taking?

• Avoid alcohol and activities requiring mental alertness until you know how risperidone affects you.

What Happens if I Miss a Dose?

• Take the missed dose as soon as you remember unless it is almost time for your next dose. Do not double doses