Lybalvi (olanzapine/samidorphan) is a brand-name prescription medication. The Food and Drug Administration (FDA) has approved it to treat the following conditions in certain adults:

For bipolar disorder, Lybalvi can be used alone for short-term or maintenance (long-term) treatment of manic or mixed episodes. It can also be used in combination with valproate or lithium to treat manic or mixed episodes.

Here are some fast facts about Lybalvi:

  • Active ingredients: olanzapine and samidorphan
  • Drug class: atypical antipsychotic and opioid antagonist
  • Drug form: oral tablet
  • FDA approval year: 2021

In some cases, if you’re taking Lybalvi for bipolar I disorder, your doctor may recommend taking it along with another drug. If Lybalvi works for you, your doctor will likely recommend that you take it long term.

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

Lybalvi can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Lybalvi in clinical trials:

  • weight gain
  • sleepiness
  • dry mouth
  • constipation
  • headache*

* For more information about this side effect, see “Side effect specifics” below.

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

Mild side effects that have been reported with Lybalvi include:

These side effects may be temporary, lasting a few days to weeks. However, 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 side effects of the medication. If you develop a side effect while taking Lybalvi and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Side effect specifics” below.

Many side effects reported by people taking Lybalvi are mild. However, serious side effects are also possible from this medication.

Lybalvi 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 Lybalvi’s prescribing information.

If you develop serious side effects while taking Lybalvi, 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:

* Lybalvi 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 taking Lybalvi. However, this side effect wasn’t reported in clinical trials.

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

Is bleeding a side effect of Lybalvi?

No, bleeding is not a side effect of Lybalvi treatment. Bleeding was not reported in clinical trials of people taking this medication.

Lybalvi may decrease your white blood cell levels as a side effect. However, this does not cause bleeding. Instead, low white blood cell levels can increase your risk of infection.

If you notice that you’re bleeding more often or more easily than is typical, tell your doctor. They can help determine what may be causing your bleeding and the best ways to treat it.

What side effects does Lybalvi cause after treatment is stopped?

You should not experience side effects after stopping treatment with Lybalvi. This medication wasn’t reported to cause withdrawal symptoms. Withdrawal symptoms occur when your body becomes used to a substance and then you suddenly stop taking it.

However, it’s important to note that one of the active ingredients in Lybalvi, samidorphan, can cause opioid withdrawal. This can occur in people who are physically dependent on opioids and take Lybalvi.

Opioid withdrawal can be severe and may need hospitalization. For this reason, do not take Lybalvi for at least 7 days after you stop taking short-acting opioids.* And do not take Lybalvi for at least 14 days after you stop taking long-acting opioids. (To learn more about opioids and Lybalvi, see the “Precautions for Lybalvi” section below.)

Also, if you stop taking Lybalvi, your condition may worsen. This medication is used to treat certain types of bipolar I disorder or schizophrenia.† So, stopping treatment with Lybalvi may cause the symptoms of your condition to come back.

If you’d like to stop taking Lybalvi, talk with your doctor. They can help determine the best way for you to stop treatment. They can also recommend other medications for your condition.

* With short-acting opioids, your body processes them more quickly than long-acting opioids.
† For details about the uses of Lybalvi, see this article.

Does Lybalvi cause certain side effects in adolescents?

Lybalvi is only approved for use in adults (ages 18 years and older). This medication wasn’t studied in children younger than 18 years old. So it’s not known what effects the drug may have on children younger than 18 years old.

In most cases, younger and older adults taking Lybalvi reported the same side effects. However, it’s possible for younger adults to have an increased risk of dystonia (unusual and continuous muscle contractions) from taking this medication.

If you’re concerned about certain side effects of Lybalvi, talk with your doctor or pharmacist.

Learn more about some of the side effects that Lybalvi may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Lybalvi.

Increased risk of death in older adults with psychosis due to dementia

Lybalvi has a boxed warning for the risk of death in older adults with psychosis due to dementia. A boxed warning is the most serious warning that the Food and Drug Administration (FDA) recommends. The purpose of a boxed warning is to alert patients and doctors about the risks of taking a medication.

It’s possible for older adults (ages 65 years and older) who have psychosis due to dementia to have an increased risk of death from any antipsychotic drug, including Lybalvi. (With psychosis, it’s hard to determine what’s real and what isn’t real. And with dementia, you have memory, thinking, and communication problems.)

In most cases, death in people with psychosis due to dementia was heart- or infection-related. It’s possible to experience heart failure or serious infection, such as pneumonia, with Lybalvi.

What you can do

Due to these risks, your doctor won’t recommend taking Lybalvi if you’re an older adult with psychosis due to dementia. They may recommend a different treatment option for your condition.

Changes in blood pressure

Some people may experience changes in blood pressure from taking Lybalvi. Specifically, this medication may cause orthostatic hypotension (low blood pressure when you change positions). This was not one of the most common side effects in clinical trials of Lybalvi.

Symptoms of orthostatic hypotension can include dizziness, blurry vision, fainting, or confusion. It may also cause lightheadedness or fainting when you get up too quickly from a sitting or lying position.

You may have an increased risk of orthostatic hypotension when you first start taking Lybalvi or when your dose is increased. (To learn about Lybalvi’s dosages, see this article.)

What you can do

If you notice symptoms of changes in blood pressure, tell your doctor right away. They may recommend monitoring your blood pressure throughout your treatment. In some cases, they may recommend a different treatment option for you.

Headache

Headache may occur during treatment with Lybalvi. Headaches were one of the most common side effects that people taking this medication reported in clinical trials.

Specifically, headaches occurred in people taking Lybalvi for schizophrenia. This side effect wasn’t reported in people taking Lybalvi to treat bipolar I disorder.

What you can do

If you experience headaches during your treatment with Lybalvi, talk with your doctor. They may recommend ways to help decrease the frequency of your headaches. They may also recommend taking an over-the-counter pain medication, such as acetaminophen (Tylenol) or ibuprofen (Advil), to treat your headaches.

High cholesterol or triglycerides

It’s possible to develop high cholesterol or triglycerides from taking Lybalvi. This was not one of the most common side effects that people taking Lybalvi reported.

High cholesterol or triglycerides don’t typically cause any symptoms.

What you can do

Your doctor may recommend testing your cholesterol and triglycerides with a blood test before you start Lybalvi treatment. Then, they may monitor your levels throughout your treatment to be sure that they don’t become too high.

If you develop high cholesterol or high triglycerides, your doctor will likely recommend that you take a medication to decrease your levels. In some cases, they may recommend a different treatment option for you.

Allergic reaction

As with most drugs, Lybalvi can cause an allergic reaction in some people. However, this side effect wasn’t reported in clinical trials.

Symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • 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 Lybalvi. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Before taking Lybalvi, talk with your doctor about any medical conditions that you have.

Boxed warning: Increased risk of death in older adults with psychosis due to dementia

This drug has a boxed warning for an increased risk of death in older adults with psychosis due to dementia. This is a serious warning from the Food and Drug Administration (FDA). 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 Lybalvi. This drug may not be the right treatment option for you if you have certain medical conditions or other factors that affect your health. These are known as drug-condition or drug-factor interactions. The conditions and factors to consider include:

Use of opioids. Tell your doctor if you are taking opioids or have taken any opioids in the past 14 days. Lybalvi can cause opioid withdrawal if you take it when you have recently taken an opioid medication. So before you start treatment with Lybalvi, your doctor will recommend you stop taking your opioid for at least 7 to 14 days. You should not start taking opioids during treatment or within 5 days after you stop treatment with Lybalvi. This is because of the increased risk of an opioid overdose, which can be fatal. Your doctor will recommend the best treatment plan for you.

Harmful use of illegal drugs. If you use illegal drugs, tell your doctor before taking Lybalvi. This is because of the risk of opioid withdrawal or a life threatening opioid overdose. (For more information, see just above.) If you use illegal drugs, your doctor may recommend a different treatment option for you.

Blood pressure problems. Tell your doctor about any blood pressure problems that you have before you start taking Lybalvi. This drug may cause low blood pressure, which can lead to fainting. If you already have low blood pressure, you may have an increased risk of this side effect. If you have high blood pressure and you take medications to decrease it, you may develop this side effect as well. Your doctor may recommend monitoring your blood pressure during your Lybalvi treatment. This is to be sure that it doesn’t get too low.

Kidney problems. If you have any kidney problems, tell your doctor before taking Lybalvi. Your kidneys get rid of Lybalvi. So if they aren’t working correctly, the drug can build up in your body, which can increase your risk of side effects. Your doctor can help determine whether Lybalvi is safe for you depending on your kidney condition.

High blood sugar or diabetes. Tell your doctor if you have high blood sugar, diabetes, or a family history of diabetes. This drug may increase your blood sugar level, which can increase your risk of diabetes or worsen diabetes if you have it. Your doctor can help determine whether Lybalvi is safe for you. In some cases, they may recommend monitoring your blood sugar more often. Or they may recommend a different treatment option for you.

High cholesterol or high triglyceride levels. If you have high cholesterol or triglycerides, tell your doctor before taking Lybalvi. This medication can cause high cholesterol or triglycerides as a side effect. So if you already have these conditions, Lybalvi can worsen your condition. Your doctor may recommend monitoring your cholesterol or triglycerides more often during your treatment. In some cases, they may recommend a different treatment option for you.

Low white blood cell count. If you have low white blood cell levels, tell your doctor before starting Lybalvi treatment. This medication can decrease levels of white blood cells, which can increase your risk of infection. If you already have low white blood cell levels, Lybalvi may lower them further. Your doctor may monitor your blood cell levels more frequently or recommend a different treatment option for you.

Trouble swallowing. It’s possible for Lybalvi to cause problems with swallowing. If you already have a condition that causes trouble swallowing, Lybalvi may make your condition worse. Your doctor can help determine whether Lybalvi is safe for you to take.

Seizures. Tell your doctor if you have a history of seizures or seizure disorders. This medication may cause seizures. And this risk may be higher if you’ve ever had seizures. Your doctor can help determine whether Lybalvi is a safe medication for you.

Digestive problems. Tell your doctor about any digestive problems that you have before starting Lybalvi treatment. This medication may cause constipation or other digestion problems, such as paralytic ileus. Your doctor can help determine whether Lybalvi is a safe treatment option for you.

Breast cancer. If you’ve ever had breast cancer, tell your doctor before taking Lybalvi. Some breast cancers may be affected by a hormone called prolactin. Lybalvi can increase your prolactin level. If you’ve ever had breast cancer, your doctor may recommend a different treatment option for you.

Trouble urinating or prostate conditions. If you have trouble urinating or any prostate conditions, tell your doctor before taking Lybalvi. This medication can increase your risk of urinary retention. So Lybalvi may worsen urinary retention or increase symptoms of your prostate condition. Your doctor can help determine whether Lybalvi is a safe medication for you.

High prolactin level. If you have a high prolactin level, tell your doctor before taking Lybalvi. This medication may increase your prolactin level. And if you already have a high level, Lybalvi may increase them further. Your doctor can help determine whether Lybalvi is safe for you to take.

Allergic reaction. If you’ve had an allergic reaction to Lybalvi or any of its ingredients, your doctor will likely not prescribe the drug. Ask your doctor what other medications may be better options for you.

Heart problems or stroke. If you’ve ever had heart problems or a stroke, tell your doctor before taking Lybalvi. This drug may increase the risk of these problems occurring. In this case, your doctor may recommend a different treatment option for you.

Alcohol with Lybalvi

Your doctor will likely recommend that you avoid alcohol during your treatment with Lybalvi. This is because alcohol can increase the risk of certain side effects, such as orthostatic hypotension. This can cause fainting or dizziness. (To learn more, see the “Side effect specifics” section above.)

If you’re taking Lybalvi, talk with your doctor to find out whether alcohol is safe for you to drink.

Pregnancy and breastfeeding while taking Lybalvi

It’s not known whether it’s safe to take Lybalvi during pregnancy. However, if you take Lybalvi during your third trimester, your child may have an increased risk of withdrawal symptoms. (Withdrawal symptoms occur when your body becomes used to a substance and then you suddenly stop taking it.) Your child may also have an increased risk of agitation, respiratory distress (trouble breathing), tremor, or differences in muscle tone or sleepiness.

When olanzapine (an active ingredient in Lybalvi) was studied during pregnancy, it didn’t seem to increase the risk of congenital anomalies in developing fetuses. (Congenital anomalies are also known as birth defects.) However, it’s not known what effects samidorphan (the other active ingredient of Lybalvi) may have on a developing fetus.

If you become pregnant while you’re taking Lybalvi, your doctor will recommend you sign up for a pregnancy registry. A pregnancy registry is a collection of information about side effects and risks of taking a medication during pregnancy. If you’re interested in signing up for a registry, talk with your doctor. You can also call 866-961-2388 or visit this website.

It’s not known whether Lybalvi may be safe to take while you’re breastfeeding. Olanzapine is known to pass into breast milk. And studies show that the drug may cause children to become sleepier than is typical, irritable, and have difficulty feeding. It’s not known what effects samidorphan may cause while breastfeeding.

If you are pregnant, planning to become pregnant, or breastfeeding, talk with your doctor before taking Lybalvi. They can help determine the best treatment option for you.

It’s possible to experience side effects from taking Lybalvi. Many side effects are mild. However, some people may experience serious side effects as well.

If you’d like to learn more about Lybalvi, talk with your doctor or pharmacist. They can help answer any questions you have about side effects of 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.