Risperidone: what it treats, how to take it, side effects
Last updated September 3, 2026.
Risperidone is an atypical antipsychotic - it changes the activity of certain natural substances in the brain. You may know it as Risperdal. It treats schizophrenia and bipolar mania, and it is also the medicine that steadies severe irritability in autistic disorder.
What does it treat?
Schizophrenia in adults and teens, bipolar mania in adults and children 10 and older, and the irritability - aggression, temper tantrums, quickly changing moods - that comes with autistic disorder in children. It controls symptoms; it does not cure the condition, and full benefit can take several weeks.
How do you take it?
Once or twice a day, with or without food, same times every day. The label starts adults with schizophrenia at 2 mg and moves toward 4 to 8 mg - your doctor starts low and raises gradually so your body adjusts. Three forms: tablets, an oral solution, and dissolving tablets. The solution: measure with the supplied dosing syringe, and you can mix it with water, orange juice, coffee, or low-fat milk - never tea or cola. The dissolving tablet: dry hands, peel the foil (never push it through), place on the tongue. Keep taking it when you feel well, and never stop without your doctor. Missed dose: take it when you remember unless the next one is close; never double up.
Side effects to know
- Common: increased appetite and weight gain, nausea or heartburn, constipation or diarrhea, dry mouth or extra saliva, anxiety, agitation or restlessness, dizziness or unsteadiness, breast enlargement or discharge, and missed menstrual periods.
- Serious - call your doctor immediately: unusual movements of the face, tongue, or body you cannot control; fever with stiff muscles, sweating, confusion, or a fast or irregular heartbeat (neuroleptic malignant syndrome); seizures; tightening of the neck or throat or trouble swallowing; a painful erection lasting hours; signs of infection like fever, cough, or chills; and rash, hives, facial swelling, or trouble breathing. High blood sugar is also a risk - extreme thirst, frequent urination, extreme hunger, blurred vision, or weakness can become ketoacidosis (fruity-smelling breath, vomiting, shortness of breath, decreased consciousness).
Who should not take it?
The boxed warning: older adults with dementia have an increased risk of death and stroke on antipsychotics, and risperidone is not approved for dementia-related behavior problems. Flag Parkinson's disease, heart problems or stroke history, high or low blood pressure, seizures, low white blood cell counts, high cholesterol, osteoporosis, breast cancer, kidney or liver disease, and diabetes or family diabetes. Risperidone raises the hormone prolactin - that is behind the breast effects and missed periods, and boys and young men can grow breast tissue, so that conversation belongs in the room for teenagers. It also blurs temperature control in both directions - pace exertion in heat and cold. The dissolving tablets contain phenylalanine, which matters with PKU. Alcohol adds to the drowsiness: do not drink while taking it. Taken in the last months of pregnancy, it can cause problems in newborns - if you become pregnant, call your doctor.
When is it an emergency?
Fever with stiff muscles and confusion, a seizure, fainting, or trouble breathing or swallowing is a 911 call. For an overdose - drowsiness, a pounding heartbeat, uncontrollable movements, seizures - call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
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Common questions
Why does risperidone carry a boxed warning?
The label's boxed warning: older adults with dementia have an increased risk of death - and a greater chance of stroke - when treated with antipsychotics. Risperidone is not approved for behavior problems in older adults with dementia. If a family member with dementia was prescribed it, that is a direct conversation with the prescriber.
Why is risperidone prescribed to autistic children?
For a specific, studied target: the irritability of autistic disorder - aggression, temper tantrums, quickly changing moods. MedlinePlus lists this as an approved use. It does not treat autism itself; it steadies the symptoms that can make a child unsafe or unable to learn. The label doses it by weight, starting as low as 0.25 mg, and weight gain is watched closely in children.
Why is my teenager's body changing on risperidone?
Risperidone raises prolactin, the hormone behind breast effects: enlargement or discharge in any sex, missed periods in girls, and - MedlinePlus names it directly - increased breast size in boys and male teenagers, plus more-than-expected weight gain in children. It is a known, monitorable effect, and it deserves an honest talk with your prescriber about whether the balance still favors the medicine.
Why can't I mix the risperidone liquid with tea or cola?
Chemistry. MedlinePlus says the oral solution mixes fine with water, orange juice, coffee, or low-fat milk - but not tea or cola, which can destabilize it. Measure with the dosing syringe it comes with, never a kitchen spoon, and take the mixed dose right away.
Can I drink alcohol while taking risperidone?
No - MedlinePlus says it directly: alcohol can add to the drowsiness this medication causes, so do not drink while taking it. Risperidone already affects clear thinking, reaction time, and balance; alcohol stacks on all three.
What happens if I miss a dose of risperidone?
Take it as soon as you remember, unless it is almost time for the next one - then skip it and never double up. Because doses start low and build, staying on schedule is part of how the titration works - gaps are what make side effects feel new again when you restart.