Rexulti (brexpiprazole) is a prescription brand-name medication. It’s approved by the Food and Drug Administration (FDA) to treat the following conditions in adults:

Here are some fast facts on Rexulti:

  • Active ingredient: brexpiprazole
  • Drug class: atypical antipsychotic
  • Drug form: oral tablet

Like other drugs, Rexulti can cause side effects. Read on to learn about potential common, mild, and serious side effects. For a general overview of Rexulti, including details about its uses, see this article.

These are just a few of the more common side effects reported by people who took Rexulti in clinical studies. These side effects can vary depending on which condition the drug is being used to treat.

More common side effects in people taking Rexulti for depression include:

More common side effects in people taking Rexulti for schizophrenia include:

  • akathisia
  • weight gain

Mild side effects can occur with Rexulti use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Rexulti’s medication guide.

Mild side effects that have been reported with Rexulti include:

These side effects may be temporary, lasting a few days or weeks. But if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect while taking Rexulti and want to tell the FDA about it, visit MedWatch.

Rexulti may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Rexulti’s medication guide.

If you develop serious side effects while taking Rexulti, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported and their symptoms include:

  • Neuroleptic malignant syndrome (a possibly life-threatening reaction to certain drugs). Symptoms can include:
    • confusion
    • fast heart rate
    • fever
    • rigid muscles
    • sweating
  • Tardive dyskinesia (unintentional muscle movements). Symptoms can include:
    • excessive blinking
    • trouble controlling movements of your face or tongue
    • waving your arms without meaning to
  • High blood sugar levels. Symptoms can include:
    • feeling unusually thirsty or hungry
    • needing to urinate more frequently than usual
    • weakness
    • tiredness
  • Orthostatic hypotension (a sudden decrease in blood pressure when changing positions). Symptoms can include:
    • dizziness when you stand up after you’ve been sitting or lying down
  • Seizures (unusual electrical activity in the brain). Symptoms can include:
    • loss of consciousness
    • confusion
    • uncontrollable movements of your arms or legs
  • Trouble swallowing caused by neck spasms (uncontrolled muscle tightening). Symptoms can include:
    • trouble breathing
    • food getting caught in your throat
  • Body temperature regulation problems. Symptoms can include:
    • trouble cooling down after you exercise or are exposed to heat
  • Stroke (decreased or blocked blood flow to the brain), which is more commonly reported in older people using Rexulti. Symptoms can include:
    • confusion
    • numbness or weakness in your arms, face, or legs
    • trouble speaking
    • trouble seeing from one or both of your eyes
  • Increased blood cholesterol or triglyceride levels. This usually doesn’t cause noticeable symptoms, but would show on blood test results.
  • Risk of death in certain older adults.*
  • Risk of suicidal thoughts and behaviors in certain people.*
  • Weight gain.†
  • Allergic reaction.*‡

* Rexulti has a boxed warning for this side effect. This is the most serious warning from the Food and Drug Administration (FDA). To learn more, see the “Side effect specifics” section below.
† For more information about this side effect, see “Side effect specifics” below.
‡ An allergic reaction is possible after using Rexulti. But this side effect wasn’t reported in clinical studies.

It’s possible to experience weight gain as a side effect of Rexulti. This was a common side effect reported in clinical studies of Rexulti regardless of the condition the drug was used to treat.

For some people, this weight gain can be serious. Some people in these trials stopped taking Rexulti due to weight gain.

How much weight you might gain can depend on a variety of factors. These include your dosage of Rexulti, your condition, your diet and your exercise level, and other conditions you have.

What you can do

While taking Rexulti, your doctor will closely monitor your weight. They may have you monitor and record your weight at home as well, to watch for increases.

If you’re concerned about your weight while taking Rexulti, talk with your doctor or pharmacist. They can recommend ways to maintain a weight that’s healthy for you. And if weight gain from Rexulti is bothering you, they can also recommend other treatments for your condition.

Learn more about some of the side effects that Rexulti may cause.

Tiredness

Tiredness is a potential side effect of Rexulti treatment. The drug may cause you to feel tired no matter how much quality sleep you’ve gotten.

To see how often tiredness occurred in clinical studies of Rexulti, see the drug’s prescribing information.

Note: Insomnia, which is a sleep disorder that involves trouble falling asleep or staying asleep, is also a possible side effect of Rexulti. See “Insomnia” just below for details.

What you can do

Your doctor may recommend that you avoid driving or operating machinery until you know whether taking Rexulti will make you tired.

Talk with your doctor or pharmacist if you have tiredness that bothers you or concerns you while taking Rexulti. They may be able to suggest ways to help improve your energy levels. They may also suggest that you stop taking Rexulti and try another medication for your condition.

Headache

You may have headaches as a side effect of Rexulti. Headaches may go away a few days or weeks after starting Rexulti treatment.

For details about how often headache occurred in clinical studies, see Rexulti’s prescribing information.

What you can do

If you’re having headaches while taking Rexulti, talk with your doctor or pharmacist. They can help determine if there may be another potential cause of your headaches. They may also suggest treatments, including an over-the-counter painkiller such as Tylenol (acetaminophen).

If you have headaches that are severe or don’t go away, your doctor may have you stop taking Rexulti and try another medication instead.

Insomnia

Although very rare, it’s possible to experience insomnia while taking Rexulti. Insomnia refers to problems falling asleep or staying asleep. This side effect wasn’t commonly reported by people taking Rexulti in clinical studies.

What you can do

Tell your doctor or pharmacist if you’re having insomnia while taking Rexulti. They may suggest ways to help with your energy levels during the day. They may also recommend a treatment to help you sleep at night, such as:

  • taking melatonin, an over-the-counter supplement that may help promote sleep
  • improving your sleep hygiene (behaviors and habits that can help with sleep quality)

Your doctor may also suggest stopping Rexulti treatment and may have you try a different medication.

Risk of death in certain older adults

Rexulti has a boxed warning about the risk of death in certain adults ages 65 years and older. A boxed warning alerts doctors and patients about drug effects that may be dangerous. It’s the most serious warning from the Food and Drug Administration (FDA).

Rexulti should not be used to treat psychosis related to dementia (memory loss) in people 65 years and older. (With psychosis, you lose touch with reality and may see or hear things that aren’t actually there.) Rexulti can increase the risk of death when used in older adults with this condition.

What you can do

Before you start taking Rexulti, your doctor will review your medical history to make sure Rexulti is a safe, effective treatment for you. If you have concerns about using Rexulti due to this boxed warning, make sure to talk with your doctor.

Risk of suicidal thoughts and behaviors in certain people

Rexulti has a boxed warning about the risk of suicidal thoughts and behaviors in adults ages 18– 24 years. A boxed warning alerts doctors and patients about drug effects that may be dangerous. It’s the most serious warning from the Food and Drug Administration (FDA).

Like other drugs used to treat depression, Rexulti has been shown to increase the risk of suicidal thoughts and behaviors in young adults. This is more likely to occur when you first start taking Rexulti and whenever your dosage is adjusted.

Keep in mind that depression and other mental health conditions also increase the risk of having suicidal thoughts and behaviors.

Note: Rexulti is only approved for use in adults. Its safety and effectiveness in children younger than 18 years has not been studied.

What you can do

Before you start taking Rexulti, your doctor will discuss these risks with you. They may also ask if you’re comfortable having someone close to you watch for noticeable changes in how you’re feeling or acting while taking Rexulti. This could be a friend, family member, or caregiver.

While you’re taking Rexulti, try to be aware of any changes, especially sudden changes, in your behaviors, feelings, moods, or thoughts. If you or those around you notice any such changes, contact your doctor right away. Your doctor may recommend stopping Rexulti and trying a different treatment for your condition.

Allergic reaction

As with most drugs, Rexulti can cause an allergic reaction in some people. But this side effect wasn’t reported in clinical studies.

Symptoms can be mild or serious and can include:

  • rash
  • itching
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin, typically in your lips, eyelids, feet, or hands
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep taking Rexulti. But if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Rexulti may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Do the side effects of Rexulti vary by strength?

Yes, the risk for certain side effects can vary depending on which strength of the drug you’re taking. Rexulti tablets are available in the following strengths:

  • 0.25 milligrams (mg)
  • 0.5 mg
  • 1 mg
  • 2 mg
  • 3 mg
  • 4 mg

In clinical studies, people taking 3 mg of Rexulti per day reported akathisia (feelings of restlessness and inability to sit still) more often than people taking 2 mg or 1 mg.

If you’d like to know more about specific side effects of Rexulti that may vary by strength, check out the medication’s prescribing information. You can also ask your doctor or pharmacist.

Can stopping Rexulti treatment cause side effects of withdrawal?

Yes, stopping Rexulti treatment could cause withdrawal. Withdrawal refers to unpleasant effects that can occur when you suddenly stop taking a drug that your body has become dependent on. (With dependence, your body needs a drug in order to feel normal.)

Withdrawal wasn’t reported in clinical trials of Rexulti. But withdrawal has been reported by people who abruptly stopped taking similar drugs, such as Abilify (aripiprazole). Abilify and Rexulti belong to the same group of drugs, called atypical antipsychotics.

Withdrawal symptoms could include:

  • sleep problems
  • irritability
  • feeling agitated or restless
  • tremors (shaking you can’t control)

Due to the risk of withdrawal, you should not stop taking Rexulti without first speaking with your doctor. If you want to stop taking Rexulti, your doctor can recommend a plan to help you taper off Rexulti. Tapering off means that your doctor will have you slowly decrease your dosage over time. This is safer than suddenly stopping the drug and can lower your risk for withdrawal.

If you have concerns about withdrawal effects with Rexulti, make sure to talk with your doctor or pharmacist.

How long do Rexulti side effects last?

It depends. Some side effects of Rexulti may be temporary and last a few days or weeks.

Most mild side effects, such as headache and tremors (shaking you can’t control), should go away on their own. But some other side effects, such as weight gain or akathisia (feelings of restlessness and inability to sit still), may not go away with time.

If you have side effects that last a long time, bother you, or become severe, be sure to talk with your doctor.

Keep reading for important precautions you should consider before taking Rexulti.

Boxed warnings

This drug has the following boxed warnings, which are serious warnings from the Food and Drug Administration (FDA):

  • risk of death in certain adults ages 65 years and older
  • risk of suicidal thoughts and behaviors in adults ages 18–24 years

For details, see the “Side effect specifics” section above.

Other precautions

Be sure to talk with your doctor about your health history before you take Rexulti. This drug may not be the right treatment for you if you have certain medical conditions or other factors that affect your health. The conditions and factors to consider include:

Diabetes. Taking Rexulti can cause increases in blood sugar levels. If you have diabetes, Rexulti may cause your blood sugar to rise to dangerous levels. Although rare, this can result in serious complications such as diabetic ketoacidosis, which can be fatal. So if you have diabetes, make sure to talk with your doctor about how to monitor your blood sugar while taking Rexulti.

Heart problems. Taking Rexulti can cause orthostatic hypotension (a sudden decrease in blood pressure when changing positions). If you have any heart problems, such as heart disease or problems with your heart’s electrical pathways, talk with your doctor before taking Rexulti. They can help determine if the drug is safe for you to take. If your doctor prescribes Rexulti for your condition, they’ll also recommend how to monitor your blood pressure during treatment.

Compulsive behaviors, including gambling. Taking Rexulti can cause or increase certain urges, including sexual desires and urges to gamble or binge eat. If you have a history of compulsive behaviors or addiction, talk with your doctor before you start taking Rexulti. They can help determine if it’s a safe medication for treating your condition.

Hyperlipidemia. With hyperlipidemia, you have high blood levels of cholesterol or triglycerides. Rexulti can make these problems worse. Talk with your doctor about whether Rexulti is safe to take, given your lipid levels.

Kidney problems or liver problems. Your body uses your kidneys and liver to metabolize (break down) and get rid of Rexulti. People with kidney problems or liver damage may need a lower dosage of Rexulti than usual. Your doctor can help determine if it’s safe for you to use Rexulti for your condition if you have kidney or liver problems.

Seizure disorders, including epilepsy. Taking Rexulti can increase the risk of seizures (unusual electrical activity in the brain). People with epilepsy or a history of seizures may be at even higher risk. Talk with your doctor about whether Rexulti is safe for you to take if you have epilepsy or a history of seizures.

Low white blood cell levels. Drugs such as Rexulti can cause leukopenia (low white blood cell levels). It’s not known if Rexulti can also cause this. But to be safe, if you have low levels of white blood cells you should talk with your doctor before you begin taking Rexulti.

Allergic reaction. You should not take Rexulti if you’ve ever had an allergic reaction to the drug or any of its ingredients. Talk with your doctor about which other treatments are better choices for you.

Alcohol use with Rexulti

It’s not known whether there may be any interactions between Rexulti and alcohol.

If you have liver damage caused by excessive alcohol use (such as alcoholic liver disease or cirrhosis), make sure to talk with your doctor about this. Having liver damage can cause Rexulti to build up in your body, which increases your risk for side effects.

If you drink alcohol, talk with your doctor about how much alcohol may be safe for you to have while taking Rexulti.

Pregnancy and breastfeeding while taking Rexulti

It’s not known whether it’s safe to take Rexulti while pregnant, because no studies have looked at the drug’s use during pregnancy. There are some reports of infants exposed to the drug during pregnancy having withdrawal symptoms, however.*

It’s also not known whether Rexulti may be safe to take while breastfeeding.

Before taking Rexulti, talk with your doctor if you’re pregnant, breastfeeding, or planning to become pregnant or breastfeed.

* Withdrawal refers to unpleasant effects that can occur when suddenly stopping a drug that your body has become dependent on. And with dependence, the body needs a drug in order to feel normal. For details, see the “Can stopping Rexulti treatment cause side effects of withdrawal?” in the “FAQs about the side effects of Rexulti” section above.

Like most drugs, Rexulti can cause some mild side effects, including some that are common. Most mild side effects of the drug go away with time and don’t require medical attention.

Serious side effects are also possible. You should talk with your doctor if you experience symptoms of any serious side effects, which are described above in the “Serious side effects of Rexulti” section. You should also talk with your doctor if you become pregnant while taking Rexulti.

If you’d like to learn more about Rexulti, talk with your doctor or pharmacist. They can help answer any questions you have about side effects from taking the drug.

Besides talking with your doctor, you can do some research on your own. These articles might help:

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.