PDR Health


What is Risperdal?

Risperdal is an antipsychotic medicine. It works by changing the effects of chemicals in the brain.

Risperdal is used to treat schizophrenia and symptoms of bipolar disorder (manic depression). It is also used to treat irritability associated with autistic disorder.

Risperdal may also be used for purposes not listed in this medication guide.


Health Benefits

Risperdal can help improve mood swings, reduce anxiety and paranoia, and make it easier to think more clearly.

It can also help control aggression, self-injurious behavior, and temper tantrums in children.

Side Effects

Common side effects of Risperdal include:


tired feeling;

dizziness, headache, shaking (tremor);

nausea, vomiting, upset stomach;

constipation; or

weight gain.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.


Risperdal is available in tablet, orally disintegrating tablet, solution, and injectable form. The usual starting dose for adults with schizophrenia is 2 mg to 3 mg per day.

For children aged 5 to 16 years old with schizophrenia or bipolar disorder, the starting dose is 0.5 mg to 1 mg per day.

For children with autistic disorder, the starting dose is 0.25 mg to 0.5 mg per day.

Your dose may be gradually increased to a maximum recommended dose of 6 mg per day for schizophrenia, 4 mg per day for bipolar disorder, and 2 mg per day for autistic disorder.

For the best effect, take Risperdal at evenly spaced times.


Risperdal can interact with other medications, herbs, or vitamins you might be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.

To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, herbs, and vitamins you are taking. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Mechanism of Action

Risperdal works by blocking dopamine and serotonin receptors in the brain. Dopamine and serotonin are neurotransmitters that help regulate mood and emotion. By blocking these receptors, Risperdal can help reduce symptoms of psychosis and mania.


Risperdal is well absorbed from the gut and reaches peak levels in the blood within 2 to 3 hours. The half-life of Risperdal is about 3 to 6 hours.

Risperdal is metabolized in the liver and excreted in the urine and feces.

Alternatives to Risperdal

There are many alternatives to Risperdal. Some common antipsychotics include:

Aripiprazole (Abilify)

Clozapine (Clozaril)

Olanzapine (Zyprexa)

Quetiapine (Seroquel)

Ziprasidone (Geodon)

Your doctor can help you choose the best medication for your needs.