Risperdal (Risperidone) Side Effects: Common and Rare

Side effects of Risperdal

Tara Moore Collection / Taxi / Getty Images

Risperdal (risperidone) is an atypical antipsychotic drug approved by the U.S. Food and Drug Administration (FDA) to treat schizophrenia, mania with bipolar I disorder, and irritability in children and adolescents with autism spectrum disorder. If you've been prescribed this medication, it's important to be aware of the potential side effects before starting treatment.

If You Experience Risperidone Side Effects

While many of risperidone's side effects are manageable, others may be serious and, in rare cases, life-threatening. If you experience mild side effects when taking this medication, speak with your healthcare provider. If your side effects are life-threatening, seek medical care immediately or call 911.

Overview of Risperidone

Risperdal is a brand name for the generic drug risperidone. Under the brand name, this medication is available in several forms: oral tablets, liquid solutions, or injectable suspension.

The oral dose of risperidone generally ranges between 1 mg and 6 mg per day, with injectable dosage ranges between 12.5 mg and 50 mg daily. In most cases, people begin at a low dose that is gradually increased until the desired therapeutic effects are achieved.

Several of Risperdal's properties can lead to side effects. Since it is antihistaminic, for instance, it may be sedating. As an alpha-adrenergic blocker, it can interfere with hormones that regulate blood flow and blood pressure.

Risperidone also has anticholinergic effects that alter the function of smooth muscles. These are the muscles that make up the internal organs.

Common Side Effects of Risperdal

The most common side effects of Risperdal, which were reported in more than 10% of the clinical trials involving this drug, included:

  • Abdominal pain or discomfort
  • Anxiety
  • Constipation
  • Cough
  • Dizziness
  • Drowsiness or sleepiness
  • Dry mouth
  • Excessive salivation
  • Fatigue
  • Fever
  • Increased appetite
  • Involuntary muscle contraction
  • Nasal congestion, runny nose, and sneezing
  • Nausea and vomiting
  • Rash
  • Tremors or slow, rigid movements
  • Upper respiratory tract infection
  • Urinary incontinence

A majority of the time, the severity of these side effects was reported as being mild to moderate.

Extrapyramidal Side Effects of Risperidone

Extrapyramidal side effects (EPS) can affect as many as one of every four people who take risperidone, although most cases are relatively mild. These side effects affect the central nervous system and cause movement problems.

Other than a previous history of EPS, there is no way to know in advance whether you'll experience these effects. There are several types of EPS that are associated with atypical antipsychotic drug use, along with a few factors that can impact your risk levels.

Types of EPS

An estimated one in five people taking atypical antipsychotics like risperidone experience a type of EPS called tardive dyskinesia. This potentially irreversible disorder is characterized by involuntary and repetitive movements, including those of the face, mouth, tongue, arms, or legs.

Movements that can occur with tardive dyskinesia include lip-smacking, grimacing, making chewing motions, rocking, rotating the ankles or legs, marching in place, sticking out the tongue, or making repetitive sounds such as humming or grunting.

Other types of EPS that may be experienced with antipsychotic drugs include:

  • Akathisia: a feeling of inner restlessness and inability to stay still, often referred to as the "rabbit syndrome"
  • Akinesia: a loss or impairment of voluntary movement
  • Dystonic reactions: intermittent and involuntary contractions of the muscles in the face, neck, trunk, pelvis, and extremities
  • Parkinsonism: a group of neurological disorders that cause movement problems similar to Parkinson's disease, including tremors, slow movement, and stiffness

Risk Factors

If you take a high dosage of risperidone, the likelihood of developing EPS appears to increase. For example, one eight-week trial found that 15% of subjects taking 2 milligrams of Risperdal experienced Parkinsonism compared to 31% of subjects taking 16 milligrams of this drug.

If you are on this drug for an extended period, your risk of EPS may also increase. Though it's important to know that, while rare, you can still develop EPS when taking Risperdal at lower doses or for short periods.

It is important to advise your doctor if you experience involuntary muscle movements or have a loss of muscle control while taking Risperdal (risperidone). If left untreated, conditions like tardive dyskinesia may become permanent.

Rare But Serious Side Effects of Risperdal

On rare occasions, exposure to atypical antipsychotics can result in a potentially life-threatening reaction. Here are some to watch for.

Neuroleptic Malignant Syndrome

Neuroleptic malignant syndrome (NMS) is a condition that occurs in 0.01% to 0.02% of people taking antipsychotic medications and is characterized by the following symptoms:

  • Altered mental state
  • High blood pressure or blood pressure fluctuations
  • High fever (over 100.4 F)
  • Loss of bladder control
  • Muscle rigidity
  • Profuse sweating
  • Respiratory problem
  • Seizures
  • Tachycardia (rapid heartbeat)

If NMS occurs, symptoms generally appear within two weeks of starting the drug. Factors that appear to increase the risk of NMS include exhaustion, dehydration, and malnutrition, with young adult males and people who have organic brain syndromes or intellectual disabilities being affected most often.

Mortality due to NMS has declined, potentially due to recognizing and intervening more quickly when this syndrome occurs. However, this syndrome is still considered a medical emergency and can lead to death if left untreated. Therefore, it's critical to obtain treatment if any of these symptoms occur.

Additional Serious Side Effects

Other rare but potentially life-threatening side effects that may occur with Risperdal use include:

  • Diabetic ketoacidosis (a dangerous build-up of acids in the blood)
  • Pancreatitis (inflammation of the pancreas)
  • Pulmonary embolism (the formation of a blood clot in the lungs)
  • Seizures
  • Stroke
  • Sudden cardiac death
  • Suicide attempts

If you are having suicidal thoughts, contact the National Suicide Prevention Lifeline at 988 for support and assistance from a trained counselor. If you or a loved one are in immediate danger, call 911.

For more mental health resources, see our National Helpline Database.

Elderly patients with dementia-related psychosis have a higher risk of death when taking antipsychotic drugs—4.5% versus 2.6% in individuals taking a placebo or sham drug. Risperdal is not approved as a treatment for this condition, so it should not be taken for this purpose.

Frequently Asked Questions

  • What is the difference between Risperidone and Risperdal?

    Risperdal is the brand name for the medication risperidone. It is sold as tablets, oral solutions, or in extended-release injectable suspensions under the names Risperdal Consta and Perseris.

  • What does Risperdal (risperidone) treat?

    Risperidone is a second-generation atypical antipsychotic used to treat schizophrenia, bipolar I disorder, and autism-related irritability. It is also sometimes prescribed off-label to treat major depressive disorder, Tourette syndrome, and post-traumatic stress disorder (PTSD).

  • How does Risperdal (risperidone) work?

    Risperidone helps balance levels of dopamine and serotonin in the brain. This can relieve symptoms related to thinking, behavior, and mood.

  • How effective is Risperdal (risperidone)?

    Research suggests that risperidone is effective for improving mental state in people with schizophrenia, even providing positive results when the schizophrenia is treatment-resistant. Other studies have found that risperidone is effective for improving mania symptoms in people with bipolar disorder.

  • Is there a drug similar to Risperdal (risperidone) that is more effective?

    Some research indicates that olanzapine is more effective than risperidone for treating negative symptoms in schizophrenia. Negative symptoms involve the absence of things that are present in most people, such as a lack of interest in the world, a lack of facial expressions, and a lack of emotional response. Aripiprazole is another medication that has efficacy similar to risperidone but with fewer side effects.

13 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Alliance on Mental Illness. Risperidone (Risperdal).

  2. U.S. Food and Drug Administration. Janssen Pharmaceutica Products, L.P.: Risperdal (risperidone) tablets/oral solution: Risperdal M-Tab (risperidone) orally disintegrating tablets.

  3. U.S. Food and Drug Administration. Label for Risperdal.

  4. Thomson SR, Chogtu B, Bhattacharjee D, Agarwal S. Extrapyramidal symptoms probably related to risperidone treatment: A case series. Ann Neurosci. 2017;24(3):155-163. doi:10.1159/000477153

  5. Stegmayer K, Walther S, van Harten P. Tardive dyskinesia associated with atypical antipsychotics: Prevalence, mechanisms and management strategies. CNS Drugs. 2018;32:135-147. doi:10.1007/s40263-018-0494-8

  6. Divac N, Prostran M, Jakovcevski I, Cerovac N. Second-generation antipsychotics and extrapyramidal adverse effects. Biomed Res Int. 2014;2014:656370. doi:10.1155/2014/656370

  7. Ware MR, Feller DB, Hall KL. Neuroleptic malignant syndrome: diagnosis and management. Prim Care Companion CNS Disord. 2018;20(0):17r02185. doi:10.4088/PCC.19r02185

  8. Osuna-Luque J, Rodriguez-Ramos A, Gamez-Del-Estal M, Ruiz-Rubio M. Behavioral mechanisms that depend on dopamine and serotonin in Caenorhabditis elegans interact with the antipsychotics risperidone and aripiprazole. Neurosci Insights. 2018;12:1179069518798628. doi:10.1177/1179069518798628

  9. Rattehalli RD, Zhao S, Guo Li B, Jayarm MB, Xia J, Sampson S. Risperidone versus placebo for schizophrenia. Cochrane Database Syst Rev. 2016;2016(12):CD006918. doi:10.1002/14651858.CD006918.pub3

  10. Meltzer HY, Lindenmayer JP, Kwentus J, Share DB, Johnson R, Jayathilake K. A six month randomized controlled trial of long acting injectable risperidone 50 and 100 mg in treatment resistant schizophrenia. Schizophren Res. 2014;154(1-3):14-22. doi:10.1016/j.schres.2014.02.015

  11. Kishi R, Ikuta T, Matsuda Y, et al. Pharmacological treatment for bipolar mania: a systemic review and network meta-analysis of double-blind randomized controlled trials. Molecular Psychiatry. 2022;27:1136-1144. doi:10.1038/s41380-021-01334-4

  12. Suresh Kumar PN, Anish PK, Rajmohan V. Olanzapine has better efficacy compared to risperidone for treatment of negative symptoms in schizophreniaIndian J Psychiatry. 2016;58(3):311-316. doi:10.4103/0019-5545.192016

  13. Khanna P, Suo T, Komossa K, et al. Aripiprazole versus other atypical antipsychotics for schizophrenia. Cochrane Database Syst Rev. 2014;2014(1):CD006569. doi:10.1002/14651858.CD006569.pub5

By Marcia Purse
Marcia Purse is a mental health writer and bipolar disorder advocate who brings strong research skills and personal experiences to her writing.