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risperidone

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Brand names: Risperdal

Atypical Antipsychotic Rx

Risperidone is a medicine used to treat certain mental disorders. It can help reduce symptoms like hallucinations, delusions, and aggression.

Drug Pricing (NADAC)

Brand Price

$4.42/unit

Generic Price

$1.56/unit

Generic Savings

65%

Generic Available

Yes (21 manufacturers)

Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →

What it does

Risperidone is used to treat schizophrenia in adults and teens.

Common side effects

Parkinsonism (slowed movement, stiffness), Restlessness, Muscle stiffness or spasms

Key warnings

Risperidone may increase the risk of death in elderly patients who have dementia-related psychosis.

How It Works

Risperidone works by changing the levels of certain natural substances in the brain. These substances are called neurotransmitters. By balancing these chemicals, risperidone can reduce symptoms of mental disorders.

How to Take It

Take risperidone exactly as your doctor tells you. You can take it once or twice a day. Your doctor may start you on a low dose and slowly increase it. You can take risperidone with or without food.

Pregnancy & Breastfeeding

Tell your doctor if you are pregnant or plan to become pregnant. Babies born to mothers who take risperidone in the last 3 months of pregnancy may have withdrawal symptoms or other problems after birth. There is a pregnancy registry to monitor outcomes in women exposed to risperidone during pregnancy. You can contact the registry at 1-866-961-2388.

Missed Dose

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule.

Storage

Store risperidone tablets at room temperature (68°F to 77°F) away from light and moisture. Keep out of reach of children.

Side Effects (from patient reports)

Based on 88,362 FDA adverse event reports.

Breast enlargement in males
24,608
Using the medicine for a condition it's not approved for
12,324
Unusual weight gain
9,446
Weight gain
9,089
The medicine is not working
7,461
Mental or emotional problem
5,947
Using the medicine for a condition it's not approved for
5,946
Harm or damage to the body
4,624
The medicine is reacting with another medicine
4,468
High levels of prolactin (a hormone)
4,449

FDA Adverse Event Report Analysis

Detailed analysis of 129,958 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2003–2025.

Total Reports

129,958

Death-Related Reports

9,958

Hospitalization Reports

39,145

Top Indication

Product Used For Unknown Indication

Gender Distribution

Female 41,449 (36%)
Male 74,269 (64%)

Age Distribution

0–17 14,871
18–44 26,227
45–64 17,690
65–74 6,257
75+ 8,377

Most Reported Adverse Reactions (FAERS)

# Reaction Reports
1 GYNAECOMASTIA 24,608
2 OFF LABEL USE 12,325
3 ABNORMAL WEIGHT GAIN 9,446
4 WEIGHT INCREASED 9,088
5 DRUG INEFFECTIVE 7,461
6 EMOTIONAL DISORDER 5,947
7 PRODUCT USE IN UNAPPROVED INDICATION 5,946
8 INJURY 4,623
9 DRUG INTERACTION 4,468
10 HYPERPROLACTINAEMIA 4,450
11 SOMNOLENCE 4,297
12 GALACTORRHOEA 3,762
13 OBESITY 3,686
14 EMOTIONAL DISTRESS 3,520
15 EXTRAPYRAMIDAL DISORDER 3,423

Reactions in Death Reports

DEATH 2,327
COMPLETED SUICIDE 1,683
TOXICITY TO VARIOUS AGENTS 961
CARDIAC ARREST 490
CARDIO-RESPIRATORY ARREST 478
PNEUMONIA 451
OVERDOSE 404
DRUG INTERACTION 401
OFF LABEL USE 384
FALL 339

Reactions in Hospitalization Reports

DRUG INEFFECTIVE 2,673
DRUG INTERACTION 2,528
OFF LABEL USE 2,384
SOMNOLENCE 1,892
FALL 1,800
PSYCHOTIC DISORDER 1,797
HOSPITALISATION 1,630
NEUROLEPTIC MALIGNANT SYNDROME 1,562
CONFUSIONAL STATE 1,555
SUICIDE ATTEMPT 1,551

Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation

Serious Warnings

Risperidone may increase the risk of death in elderly patients who have dementia-related psychosis. Risperidone is not approved for treating dementia-related psychosis.

Known Drug Interactions

Dose adjustment is not recommended for risperidone tablets when co-administered with ranitidine, cimetidine, amitriptyline, or erythromycin [see Table 18 ] . Do not exceed twice the patient’s usual dose Enzyme (CYP3A) inhibitors Ranitidine 150 mg twice daily 1 mg single dose 1.2 1.4 Dose adjustment not needed Cimetidine 400 mg twice daily 1 mg single dose 1.1 1.3 Dose adjustment not needed Erythromycin 500 mg four times daily 1 mg single dose 1.1 0.94 Dose adjustment not needed Other Drugs Amitriptyline 50 mg twice daily 3 mg twice daily 1.2 1.1 Dose adjustment not Needed *Change relative t...

Mechanism: Amitriptyline causes a very small increase in risperidone levels in the body, but the change is not large enough to be significant.

What to do: No dose adjustment is needed when these two medications are taken together.

7 DRUG INTERACTIONS Carbamazepine and other enzyme inducers decrease plasma concentrations of risperidone. ( 7.1 ) 7.1 Pharmacokinetic-related Interactions The dose of risperidone tablets should be adjusted when used in combination with CYP2D6 enzyme inhibitors (e.g., fluoxetine, and paroxetine) and enzyme inducers (e.g., carbamazepine) [see Table 18 and Dosage and Administration (2.5) ]. Do not exceed 8 mg/day 20 mg/day 4 mg/day 1.6 - 40 mg/day 4 mg/day 1.8 - Enzyme (CYP3A/ PgP inducers) Inducers Carbamazepine 573 ± 168 mg/day 3 mg twice daily 0.51 0.55 Titrate dose upwards.

Mechanism: Carbamazepine speeds up how fast your body breaks down risperidone, which lowers the amount of medicine in your blood.

What to do: Your doctor may need to increase your dose of risperidone to make sure the medicine still works effectively.

major lithium

Do not exceed twice the patient’s usual dose Enzyme (CYP3A) inhibitors Ranitidine 150 mg twice daily 1 mg single dose 1.2 1.4 Dose adjustment not needed Cimetidine 400 mg twice daily 1 mg single dose 1.1 1.3 Dose adjustment not needed Erythromycin 500 mg four times daily 1 mg single dose 1.1 0.94 Dose adjustment not needed Other Drugs Amitriptyline 50 mg twice daily 3 mg twice daily 1.2 1.1 Dose adjustment not Needed *Change relative to reference Effect of Risperidone on other drugs Lithium Repeated oral doses of risperidone tablets (3 mg twice daily) did not affect the exposure (AUC) or pe...

Mechanism: Taking risperidone does not change the amount of lithium that stays in your bloodstream or how your body handles it.

What to do: No dose changes are necessary for lithium when it is used at the same time as risperidone.

Dose adjustment is not recommended for risperidone tablets when co-administered with ranitidine, cimetidine, amitriptyline, or erythromycin [see Table 18 ] . Do not exceed twice the patient’s usual dose Enzyme (CYP3A) inhibitors Ranitidine 150 mg twice daily 1 mg single dose 1.2 1.4 Dose adjustment not needed Cimetidine 400 mg twice daily 1 mg single dose 1.1 1.3 Dose adjustment not needed Erythromycin 500 mg four times daily 1 mg single dose 1.1 0.94 Dose adjustment not needed Other Drugs Amitriptyline 50 mg twice daily 3 mg twice daily 1.2 1.1 Dose adjustment not Needed *Change relative t...

Mechanism: Erythromycin can slightly change how your body processes risperidone, but the effect is too small to matter.

What to do: You do not need to change your dose of risperidone when taking this antibiotic.

Dose adjustment is not recommended for risperidone tablets when co-administered with ranitidine, cimetidine, amitriptyline, or erythromycin [see Table 18 ] . Do not exceed twice the patient’s usual dose Enzyme (CYP3A) inhibitors Ranitidine 150 mg twice daily 1 mg single dose 1.2 1.4 Dose adjustment not needed Cimetidine 400 mg twice daily 1 mg single dose 1.1 1.3 Dose adjustment not needed Erythromycin 500 mg four times daily 1 mg single dose 1.1 0.94 Dose adjustment not needed Other Drugs Amitriptyline 50 mg twice daily 3 mg twice daily 1.2 1.1 Dose adjustment not Needed *Change relative t...

Mechanism: Ranitidine causes a small increase in risperidone levels, but it is not enough to change how the drug works or its safety.

What to do: No dose adjustment is necessary when these two medications are used together.

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Common Questions

What should I avoid while taking risperidone?
Be careful when driving or operating machinery until you know how risperidone affects you.
Can risperidone cause weight gain?
Yes, weight gain is a common side effect of risperidone. Talk to your doctor about managing your weight.
Does risperidone interact with other medications?
Yes, risperidone can interact with other medications. Tell your doctor about all the medicines you take, including prescription and over-the-counter drugs, vitamins, and herbal supplements.
How long does it take for risperidone to work?
It may take several weeks for you to feel the full effects of risperidone.
Can I stop taking risperidone suddenly?
Do not stop taking risperidone without talking to your doctor. Stopping suddenly can cause withdrawal symptoms.
What if I experience side effects?
Tell your doctor if you experience any side effects while taking risperidone.
Can risperidone cause diabetes?
Risperidone can increase your risk of developing high blood sugar and diabetes. Your doctor may monitor your blood sugar levels.
Will risperidone make me sleepy?
Sleepiness is a common side effect of risperidone, especially when you first start taking it.
Can I drink alcohol while taking risperidone?
Avoid drinking alcohol while taking risperidone, as it can worsen side effects like sleepiness.
What should I do if I have trouble swallowing the tablet?
Talk to your doctor or pharmacist. There may be other forms of risperidone available.
What are the common side effects of risperidone?
The most commonly reported side effects of risperidone include Parkinsonism (slowed movement, stiffness), Restlessness, Muscle stiffness or spasms, Tremors, Sleepiness. Based on 88,362 FDA adverse event reports. Always consult your healthcare provider about potential side effects.
Does risperidone interact with other medications?
Yes, risperidone has 20 known drug interactions. Notable interactions include amitriptyline, carbamazepine, lithium. Always inform your doctor about all medications you are taking.
What drug class is risperidone?
risperidone belongs to the Atypical Antipsychotic drug class. It requires a prescription (Rx). Risperidone is used to treat schizophrenia in adults and teens.
Is there a generic version of risperidone?
Yes, generic risperidone is available from 21 manufacturers. The generic costs $1.56 per unit compared to $4.42 for the brand version, saving approximately 65%. Pricing is based on NADAC (National Average Drug Acquisition Cost) data from CMS.
Is risperidone safe during pregnancy?
Tell your doctor if you are pregnant or plan to become pregnant. Babies born to mothers who take risperidone in the last 3 months of pregnancy may have withdrawal symptoms or other problems after birth. Always consult your healthcare provider before using any medication during pregnancy or breastfeeding.

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Related Health & Safety Data

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What the FDA Data Shows for risperidone

The FDA label for risperidone (sold under brand names such as Risperdal) classifies it as a prescription-only medication in the Atypical Antipsychotic class. Risperidone is used to treat schizophrenia in adults and teens. Official labeling lists 25 commonly reported side effects, including Parkinsonism (slowed movement, stiffness), Restlessness, Muscle stiffness or spasms.

Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 88,362 voluntary reports. The database also lists 20 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated major severity. NADAC pricing from CMS shows a generic unit cost of $1.56 versus $4.42 for the brand — a 65% generic savings.

Report counts do not establish causation — a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice — always consult a licensed healthcare provider before starting, stopping, or changing any medication.

Data Sources

Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).

FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.

Last updated: January 9, 2026

All federal data sources used on this page