Milsaperidone: what it treats, how to take it, side effects
Last updated September 7, 2026.
**Milsaperidone, sold as Bysanti, is a prescription atypical antipsychotic for adults.** It changes dopamine and serotonin signaling in your brain. Its boxed warning concerns increased death risk in older adults with dementia-related psychosis; it is not approved for that use.
What does it treat?
You may receive milsaperidone for schizophrenia, which can involve hearing voices, false beliefs, or disorganized thinking. It also treats acute manic or mixed episodes in bipolar I disorder, involving unusually high energy, little sleep, or racing thoughts, sometimes alongside depressive symptoms. Your clinician assesses your symptom history before choosing treatment.
How do you take it?
Take tablets twice daily, with or without food. The usual adult starting dose is 1 mg twice daily, increased under supervision over 5 to 7 days. Maintenance is 6 to 12 mg twice daily for schizophrenia or 12 mg twice daily for bipolar mania; the ceiling is 24 mg daily. Some people need lower doses. Take a missed dose when remembered unless the next is near; never double. After 3 or more days off, contact your prescriber before restarting. Stop and get help for fainting or fever with rigid muscles.
Side effects to know
- Common: You may experience dizziness, sleepiness, dry mouth, fatigue, stuffy nose, weight gain, or lightheadedness when standing.
- Serious: Stop taking it and get emergency help for throat swelling, fainting with an irregular heartbeat, or fever with muscle rigidity and confusion. Report new uncontrollable movements promptly.
Who should not take it?
Do not take it if you are allergic to its ingredients. Discuss long QT, heart disease, low potassium or magnesium, seizures, diabetes, low white blood cells, and liver disease; severe liver impairment makes it unsuitable. Have your clinician check all medicines for interactions. Avoid alcohol. Discuss pregnancy before changing treatment, and do not breastfeed during treatment or the required waiting period afterward.
When is it an emergency?
For overdose, call Poison Control at 1-800-222-1222 immediately; signs include extreme sleepiness, rapid heartbeat, or seizures. Call 911 for collapse, breathing trouble, seizure, or inability to wake. Throat swelling, fever with rigid muscles and confusion, or a prolonged painful erection requires emergency care.
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Common questions
What is the maximum daily dose?
The usual adult ceiling is 24 mg, divided into two doses. Your prescribed limit may be lower. CYP2D6 poor metabolizers use a maximum of 6 mg twice daily.
Can I drink alcohol?
Avoid alcohol during treatment. It can worsen sleepiness and dizziness. Do not drive until you know how the medicine affects you.
Can I take it during pregnancy or breastfeeding?
Contact your prescriber if you become pregnant. Third trimester exposure can cause newborn movement, feeding, breathing, or withdrawal problems. Do not breastfeed during treatment or for 6 days after your last dose if you are a CYP2D6 normal metabolizer, or 8 days if you are a poor metabolizer.
Do I need to take it with food?
You can take it with or without food. Keep consistent morning and evening dosing times. Ask your pharmacist before consuming grapefruit.
What should I do after an extra dose?
Call Poison Control at 1-800-222-1222 without waiting for symptoms. Overdose can cause severe sleepiness, rapid heartbeat, and seizures. Call 911 for collapse or breathing trouble.
Which medicines interact with milsaperidone?
Fluoxetine, paroxetine, and ketoconazole can require a lower dose. Avoid combinations with medicines that prolong QT or alpha blockers. Other blood pressure medicines also need review. Give your pharmacist your complete medication list before making changes.