As of 2019, over 51 million American adults are reported to have experienced mental health problems. Two very serious mental health conditions, bipolar disorder and schizophrenia, can be difficult to treat. While some mental health problems can be managed with talk therapy alone, these two conditions typically require both therapy and medication to control symptoms.

Schizophrenia is a serious mental disorder in which people interpret reality abnormally. Schizophrenia may result in some combination of hallucinations, delusions, and extremely disordered thinking and behavior that impairs daily functioning, and can be disabling.

People with schizophrenia require lifelong treatment. Early treatment may help get symptoms under control before serious complications develop and may help improve the long-term outlook.

Bipolar disorder, formerly called manic depression, is a mental health condition that causes extreme mood swings that include emotional highs (mania or hypomania) and lows (depression).

When you become depressed, you may feel sad or hopeless and lose interest or pleasure in most activities. When your mood shifts to mania or hypomania (less extreme than mania), you may feel euphoric, full of energy or unusually irritable. These mood swings can affect sleep, energy, activity, judgment, behavior and the ability to think clearly.

Episodes of mood swings may occur rarely or multiple times a year. While most people will experience some emotional symptoms between episodes, some may not experience any.

Although bipolar disorder is a lifelong condition, you can manage your mood swings and other symptoms by following a treatment plan. In most cases, bipolar disorder is treated with medications and psychological counseling (psychotherapy).

Antipsychotics are a class of medications considered to be a mainstay of treating schizophrenia as well as an effective treatment option for managing manic symptoms of bipolar disorder. And while they are effective, they do come with unwanted side effects, such as weight gain. However, pharmaceutical manufacturer Alkermes recently announced the FDA approval of Lybalvi (olanzapine/samidorphan), a new antipsychotic option that causes less weight gain than others.

Read below to learn more about what Lybalvi is, what to expect if you take this medication, and when it is expected to be available.

What is Lybalvi?

Lybalvi is a combination of two medications: olanzapine and samidorphan. Olanzapine is a second-generation antipsychotic (also called an “atypical antipsychotic”) that has previously been sold by itself under the brand name Zyprexa.

Samidorphan is a new medication that hasn’t been previously FDA-approved. It belongs to a class of medications called opioid antagonists (also known as opioid blockers) and is related to both naltrexone (Vivitrol) and naloxone (Narcan). Up until now, no opioid blockers have been approved to treat mental health conditions.

How does Lybalvi work for treating bipolar disorder and schizophrenia?

While scientists are still researching exactly why it works, the olanzapine in Lybalvi is believed to treat these conditions by stopping two hormones — dopamine and serotonin — from having effects in parts of the brain. Olanzapine attaches to these hormone receptors and prevents them from causing hallucinations, delusions, and manic symptoms.

Samidorphan does not treat bipolar disorder or schizophrenia symptoms. Instead, it helps prevent weight gain that is typical with olanzapine. While researchers are still investigating why this medication helps manage this side effect, early animal studies suggest it may have multiple effects on the body’s overall metabolism that lead to less weight gain over time.

How is Lybalvi dosed?

Lybalvi is a once-daily oral tablet. You can take it with or without food at any time of the day as long as you take it at the same time every day. It’s important to swallow Lybalvi whole. Don’t cut, crush, or chew the tablets.

Lybalvi will be available in the following strengths:

• 5 mg olanzapine and 10 mg samidorphan
• 10 mg olanzapine and 10 mg samidorphan
• 15 mg olanzapine and 10 mg samidorphan
• 20 mg olanzapine and 10 mg samidorphan

The strength you take would be determined by your healthcare provider and varies depending on your condition.

What are the known side effects of Lybalvi?

Even though Lybalvi may cause less weight gain than olanzapine alone, it’s still the most common side effect of this medication. In its clinical trial, people taking Lybalvi gained an average of 4% of their starting weight.

Other common side effects include:

• Sleepiness
• Dry mouth
• Headache

Less common side effects include:

• Dizziness
• High blood sugar
• High cholesterol
• Low white blood cells
• Changes to liver blood tests

Like other antipsychotic-containing medications, Lybalvi can cause uncontrollable movements like tremors, muscle twitches, and a general feeling that you can’t keep still. Rarely, these movements can involve the face, tongue, and mouth. This is called tardive dyskinesia and can interfere with your ability to talk, eat, and drink. Contact your healthcare provider right away if you notice any unusual body movements after starting Lybalvi.

All antipsychotic medications, including Lybalvi, can raise your risk of seizures. This is more likely to happen if you have a seizure condition, such as epilepsy. Be sure your provider is aware if you’ve ever had a seizure before starting Lybalvi.

Very rarely, antipsychotic medications can cause a life-threatening complication called neuroleptic malignant syndrome (NMS). Signs of NMS include fever, stiff muscles, racing heart, and difficulty speaking. If you notice any of these changes after starting Lybalvi, seek medical attention right away.

Severe allergic reactions, while rare, are possible with Lybalvi. There have been cases of life-threatening allergic rashes with olanzapine that are accompanied by fevers and organ damage. If you notice a rash appear after starting Lybalvi, contact your provider immediately.

Does Lybalvi interact with other medications?

Yes. Because samidorphan is an opioid blocker, you cannot take Lybalvi if you also take opioids or if you are taking medications for opioid use disorder. This combination can cause you to experience sudden and severe opioid withdrawals.

Since sleepiness is a common side effect of Lybalvi, you should be careful taking other medications that also cause drowsiness. If avoiding this combination is not possible, you should be very cautious, as you may experience more intense sleepiness from the mixture than either medication would cause on its own. Avoid driving a vehicle or performing other activities that require alertness until you know how Lybalvi affects you.

Medications used to treat Parkinson’s disease are less effective when combined with Lybalvi. If you take medications to treat Parkinson’s disease, such as Rytary (carbidopa/levodopa), it is recommended to avoid antipsychotics, including Lybalvi.

These are not the only medications that interact with Lybalvi, just some of the most notable. Be sure to provide your prescriber and pharmacist a complete and current list of all medications, over-the-counter products, supplements, and herbal remedies you take before starting Lybalvi.

How does Lybalvi compare to other antipsychotic medications like olanzapine?

So far, Lybalvi has only been compared in studies directly to one other mental health medication — olanzapine by itself. This was one of the clinical trials that earned Lybalvi its FDA approval. Researchers found that Lybalvi was similarly effective but had significantly less weight gain than olanzapine.

While those taking olanzapine alone gained an average of 6.6% of their body weight, those taking Lybalvi only gained an average of 4% of their starting weight. People taking Lybalvi were also less likely to gain 10% or more of their body weight than people taking olanzapine. The study also noted that participants taking Lybalvi had less waist circumference growth — a measurement that can raise your risk for other health conditions, such as type 2 diabetes.

How much will Lybalvi cost?

Currently, Alkermes has not released the expected cost for Lybalvi. Typically, medication prices are not disclosed until shortly before the medication is available to be dispensed at pharmacies. However, we expect that it will be costly and comparable to other brand-name antipsychotic medications, which typically range from $500 to $1,000 without insurance.

When will Lybalvi be available?

Lybalvi is expected to be available towards the end of this year. Alkermes is hoping to release this medication in either October or November 2021. Since there are still a few months left until you can expect to see it on shelves, now is a good time to discuss whether Lybalvi could be an option for you with your provider. If you’re already taking olanzapine, this could be an easy switch.

The bottom line

Lybalvi is a combination medication that was recently FDA-approved to treat bipolar disorder and schizophrenia. This new medication provides people with an effective option that may help prevent some side effects. One of the two ingredients, samidorphan, has been shown to lower the likelihood of gaining weight while taking Lybalvi compared to taking olanzapine (the second ingredient) by itself. Speak with your provider to see if Lybalvi could be the right choice for you, and check back with GoodRx this fall for savings.