Risperidone is an atypical antipsychotic that is used to treat resistant major depression and psychotic disorders, schizophrenia, and bipolar disorder (Brunton, 2018, p. 276). It acts by increasing the levels of certain chemicals in the brain (neurotransmitters). It relieves psychotic symptoms such as hallucinations, delusions, confusion, disturbed thoughts and lack of insight or self-awareness.
Some of the specific uses of risperidone are: to treat schizophrenia in adults and children who are at least 13 years old; to treat symptoms of bipolar disorder (manic depression) in adults and children who are at least 10 years old; and to treat symptoms of irritability in autistic children who are 5 to 16 years old. Risperidone is preferable to first-generation antipsychotics because it causes fewer side effects, especially extrapyramidal symptoms which occur very rarely. Risperidone is available under the brand names Risperdal, Risperdal Consta, and Risperdal M-Tab.
Uses of Risperdal
Risperidone finds use in the treatment of psychotic symptoms of schizophrenia in adults and children who are at least 13 years old.
Long-acting intramuscular (LAI) risperidone is approved for bipolar maintenance treatment as monotherapy or adjunctively with lithium or valproate. If LAI risperidone is used as monotherapy, coverage with an oral antipsychotic is necessary for the first 4 weeks after the initial injection. When antipsychotic drugs have been employed as adjunctive agents, the optimal duration of treatment is 6 months after remission from an acute manic episode (Brunton, 2018, p. 296).
Risperidone is approved in child and adolescent bipolar disorder (acute mania) for ages 10–17; risperidone is also FDA-approved for irritability associated with autism in child and adolescent patients ages 5–16 (Brunton, 2018, p. 293).
There is a benefit of adjunctive treatment with risperidone for obsessive-compulsive disorder, with a recent meta-analysis showing significant efficacy for risperidone but not for quetiapine and olanzapine.
For generalized anxiety disorder, clinical trials demonstrated efficacy for quetiapine as monotherapy and for adjunctive low-dose risperidone. Recent data do not support the routine use of risperidone for posttraumatic stress disorder (Brunton, 2018, p. 289).
Risperidone is efficacious for agitation and psychosis in Alzheimer’s disease, but its use is often limited by adverse effects, including parkinsonism, sedation, and falls (Brunton, 2018, p. 334).
Dose of Risperidone
Note that the below doses are adult doses, except where specified. Children will require lower doses. Some effects may be noticed within a few days but it may take up to three to four weeks for the full effects of risperidone to be seen.
Dose in Schizophrenia (Brunton, 2018, p. 283) (Sinha, 2019)
Acute psychosis, 1st episode: 2-4 mg/day
Acute psychosis, chronic: 3-6 mg/day
Maintenance, 1st episode: 2-6 mg/day
Maintenance, chronic: 3-8 mg/day
The initial dose is 2 mg orally per day. It may be increased in steps of 1 to 2 mg per day at interval of 24 hours or more, as tolerated. The maintenance dose is 2 to 8 mg orally per day. The maximum dose is 16 mg orally per day.
Dose in Bipolar Disorder (Sinha, 2019)
Oral: Initially, 2-3 mg/day. If necessary, it may be increased in steps of 1 mg/day at intervals of 24 hours up to a maximum dose of 6 mg/day.
Intramuscular (IM): 12.5-50 mg every 2 weeks; dosage should not be adjusted more frequently than every 4 weeks. Establish tolerability of oral risperidone before initiating treatment with IM risperidone.
Dose in Autism
“Risperidone and aripiprazole have FDA approval for irritability associated with autism in child and adolescent patients ages 5–16, with common use for disruptive behavior problems in autism and forms of mental retardation. Initial risperidone daily doses are 0.25 mg for patients weighing less than 20 kg and 0.5 mg for others, with a target dose of 0.5 mg/day in those weighing less than 20 kg and 1.0 mg/day for other patients, with a range of 0.5–3.0 mg/day” (Brunton, 2018, p. 290).
Dose in Dementia
The doses for patients with dementia are one-fourth of adult schizophrenia doses, 0.5–1.5 mg/day (Brunton, 2018, p. 281).
What if I miss a dose? (Sinha, 2019)
Take the missed dose as soon as you remember. But, skip it if it is almost time for the next scheduled dose. Do not take two doses at once.
What if I overdose? (Sinha, 2019)
Overdose symptoms include severe drowsiness, increased heart rate, light-headedness, fainting, and restless muscle movements in your eyes, tongue, jaw, or neck. If some of these symptoms occur, seek emergency medical help immediately.
Risperidone Side Effects (Ritter, et al., 2020, p. 597) (Cunha, 2018) (Sinha, 2019) (WebMD, n.d.)
Common side effects of risperidone include:
- Drowsiness and dizziness
- Agitation and anxiety
- Stuffy or runny nose
- Changes in vision, including blurred vision
- Difficulty concentrating
- Difficulty speaking or swallowing
- Increased appetite
- Weight gain
- Urinary incontinence
- Dry mouth, nausea, indigestion, vomiting, constipation, abdominal pain
- ECG changes – QT prolongation
- Male breast enlargement in children
- Palpitation, chest pain
- Dizziness upon standing too quickly, due to sudden fall in BP (orthostatic hypotension)
- Sexual dysfunction
Less common side effects of risperidone include:
- Increased cholesterol
- Low white blood cells– symptoms of sudden weakness or ill feeling, cold or flu symptoms, cough, trouble breathing, sore throat, mouth sores, red or swollen gums, trouble swallowing, skin sores.
- Low levels of platelets in your blood– easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin.
- Allergic reaction: Get medical help right away if you notice any of these symptoms: fever, swollen lymph nodes, rash, itching/swelling (especially of the face/tongue/ throat), severe dizziness, trouble breathing.
- Extrapyramidal symptoms at high doses:
- Acute dystonias: involuntary movements (restlessness, muscle spasms, protruding tongue, fixed upward gaze, neck muscle spasm). They occur commonly in the first few weeks, often declining with time, and are reversible on stopping drug treatment.
- Tardive dyskinesia: It develops after months or years of treatment. It consists of involuntary movements, often of the face and tongue, but also of trunk and limbs.
- Neuroleptic malignant syndrome: Symptoms of fever, muscle stiffness or pain or weakness, severe tiredness, severe confusion, sweating, fast/irregular heartbeat, dark urine, change in the amount of urine.
Precautions While Taking Risperidone (Sinha, 2019) (Cunha, 2018)
Avoid driving or hazardous activity until you know the effect of risperidone on you because your reactions could be impaired.
Avoid getting up too fast from a sitting or lying position, because you may feel dizzy due to sudden fall in BP. This can cause falls, fractures, or other injuries.
Do not drink alcohol while on risperidone because dangerous side effects could occur.
Drink plenty of fluids, especially in hot weather and during exercise, because risperidone can make you sensitive to extremes of temperature.
Risperidone is not approved for the treatment of dementia-related psychosis because of the increased risk of death.
Stop using risperidone and seek emergency medical help if you have the following symptoms: fever, stiff muscles, confusion, sweating, fast or uneven heartbeats, restless muscle movements in face or neck, tremor, trouble swallowing or breathing, light-headedness, or fainting.
Consult your doctor if you are pregnant or breastfeeding. Use in pregnancy is limited to cases where the benefits outweigh the risks. It may not be advisable to take this medicine if you are breastfeeding because it can get secreted in milk, which can harm the infant.
Interactions with Risperdal (Cunha, 2018) (Sinha, 2019)
Risperidone has no known severe interactions with other drugs, serious interactions with around 30 different drugs, moderate interactions with over 350 different drugs, and mild interactions with around 30 different drugs.
Tell your doctor about all your other medicines, especially:
- BP medication
- Fluoxetine (Prozac) or paroxetine (Paxil)
The above list is not complete. Other drugs may interact with risperidone, including over-the-counter medicines, vitamins, and herbal products.
Brunton, L., 2018. Goodman & Gilman’s The Pharmacological Basis of Therapeutics. 13 ed. New York: McGraw Hill.
Cunha, J., 2018. Risperidone. [Online]
Available at: https://www.rxlist.com/consumer_risperidone_risperdal_risperdal_consta/drugs-condition.htm
[Accessed 30 Aug 2019].
Ritter, J. et al., 2020. Rang and Dale’s Pharmacology. 9 ed. Edinburgh: Elsevier.
Sinha, S., 2019. Risperidone. [Online]
Available at: https://www.drugs.com/risperidone.html
[Accessed 30 Aug 2019].
WebMD, n.d. Risperidone. [Online]
Available at: http://www.webmd.com/drugs/2/drug-6283-2034/risperidone-oral/risperidone-oral/details
[Accessed 30 Aug 2019].