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Olanzapine and samidorphan

Generic name: olanzapine and samidorphan [ oh-LAN-za-peen-and-SAM-i-DOR-fan ]
Brand name: Lybalvi
Dosage form: oral tablet (10 mg-10 mg; 15 mg-10 mg; 20 mg-10 mg; 5 mg-10 mg)
Drug class: Psychotherapeutic combinations

Medically reviewed by on Nov 15, 2021. Written by Cerner Multum.

What is olanzapine and samidorphan?

Olanzapine and samidorphan is a combination antipsychotic medicine that is used to treat schizophrenia in adults.

Olanzapine and samidorphan is also used to treat manic or mixed episodes in adults with bipolar I disorder. olanzapine and samidorphan is sometimes used together with lithium or valproate to treat these conditions.

Olanzapine and samidorphan may also be used for purposes not listed in this medication guide.


Olanzapine and samidorphan is not approved for use in older adults with dementia-related psychosis.

Before taking this medicine

You should not use olanzapine and samidorphan if you are allergic to olanzapine or samidorphan.

Do not take this medicine if you use opioid medication or you are going through withdrawal from opioid dependency. Opioids include oxycodone, morphine, hydrocodone, buprenorphine, fentanyl, and others.

Samidorphan can interact with opioid medication and cause a fatal overdose or severe opioid withdrawal that may need to be treated in a hospital.

Tell your doctor if you have used an opioid medication within the past 7 to 14 days. Be sure to tell your doctor the specific type of opioid medicine you used (such as controlled-release, extended-released, or transdermal skin patch).

Olanzapine and samidorphan may increase the risk of death in older adults with dementia-related psychosis and is not approved for this use.

Tell your doctor if you have ever had:

Taking antipsychotic medicine in the last 3 months of pregnancy may cause serious problems in the newborn. Tell your doctor right away if you get pregnant. Do not stop the medicine without your doctor's advice.

It may be harder for you to get pregnant while you are using this medicine. If you are pregnant, your name may be listed on a pregnancy registry to track the effects of olanzapine and samidorphan on the baby.

Olanzapine can pass into breast milk. If you are breastfeeding, tell your doctor if you notice severe drowsiness, irritability, feeding problems, tremors, or unusual muscle movements in the nursing baby.

Not approved for use by anyone younger than 18 years old.

How should I take olanzapine and samidorphan?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

You may take olanzapine and samidorphan with or without food.

Swallow the tablet whole and do not crush, chew, or break it.

Do not change your dose or stop using this medicine without your doctor's advice.

Olanzapine can cause high blood sugar (hyperglycemia). If you are diabetic, check your blood sugar levels on a regular basis.

Drink plenty of liquids while you are taking this medicine.

You may gain weight or have high cholesterol and triglycerides (types of fat) while taking this medicine. You may need frequent blood tests.

Read the Patient Wallet Card about a dangerous interaction with opioid medication. Keep the card with you at all times. In an emergency, your medical caregivers will need to know that you take olanzapine and samidorphan.

Store tightly closed at room temperature, away from moisture and heat. Keep the tablets in their original container, along with the packet or canister of moisture-absorbing preservative.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking olanzapine and samidorphan?

Avoid drinking alcohol.

It is easier to become dangerously overheated and dehydrated while you are taking olanzapine and samidorphan. Avoid exercising too much, being in sunlight, or being outside in hot weather. Avoid wearing heavy clothing.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Avoid driving or hazardous activity until you know how this medicine will affect you. Dizziness or drowsiness can cause falls, accidents, or severe injuries.

Olanzapine and samidorphan side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Seek medical treatment if you have a serious drug reaction that can affect many parts of your body. Symptoms may include skin rash, fever, swollen glands, muscle aches, severe weakness, unusual bruising, or yellowing of your skin or eyes.

Long-term use of olanzapine and samidorphan can cause a serious movement disorder that may not be reversible. The longer you use olanzapine and samidorphan, the more likely you are to develop this disorder, especially if you are a woman or an older adult.

Samidorphan can make you more sensitive to the effects of opioid medicine, and you could have a fatal opioid overdose. If you use opioid medicine, a person caring for you should seek emergency medical attention if you have severe dizziness or drowsiness, confusion, slow breathing with long pauses, or if you are hard to wake up.

Olanzapine and samidorphan may cause serious side effects. Call your doctor at once if you have:

  • a light-headed feeling, like you might pass out;

  • uncontrolled muscle movements in your face (chewing, lip smacking, frowning, tongue movement, blinking or eye movement);

  • trouble swallowing;

  • a seizure;

  • impotence, sexual problems, missed menstrual periods, breast swelling or discharge;

  • low white blood cell counts--fever, chills, weakness, sore throat, cough, mouth sores, skin sores;

  • signs of a stroke--sudden numbness or weakness, severe headache, slurred speech, problems with vision or balance;

  • high blood sugar--increased thirst, increased urination, dry mouth, fruity breath odor; or

  • severe nervous system reaction--very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out.

Common side effects of olanzapine and samidorphan may include:

  • increased appetite, weight gain;

  • dizziness, drowsiness, weakness;

  • problems with speech or memory;

  • tremor, numbness, tingling, burning pain;

  • headache;

  • dry mouth, upset stomach, constipation;

  • back pain; or

  • increased salivation.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Olanzapine and samidorphan dosing information

Usual Adult Dose for Schizophrenia:

Initial dose: Olanzapine 5 mg-samidorphan 10 mg OR olanzapine 10 mg-samidorphan 10 mg orally once a day
Maintenance dose: Olanzapine 10 mg-samidorphan 10 mg to olanzapine 20 mg-samidorphan 10 mg orally once a day
Maximum dose: Olanzapine 20 mg-samidorphan 10 mg/day

Comment: Doses may be increased in weekly intervals of 5 mg (olanzapine component), based on response and tolerance.

Use: Treatment of schizophrenia

Usual Adult Dose for Bipolar Disorder:

-Initial dose: Olanzapine 10 mg-samidorphan 10 mg OR olanzapine 15 mg-samidorphan 10 mg orally once a day
-Maintenance dose: Olanzapine 5 mg-samidorphan 10 mg to olanzapine 20 mg-samidorphan 10 mg orally once a day
-Maximum dose: Olanzapine 20 mg-samidorphan 10 mg/day

Adjunctive to lithium or valproate:
-Initial dose: Olanzapine 10 mg-samidorphan 10 mg orally once a day
-Maintenance dose: Olanzapine 10 mg-samidorphan 10 mg to olanzapine 20 mg-samidorphan 10 mg orally once a day
-Maximum dose: Olanzapine 20 mg-samidorphan 10 mg/day

-Initial recommended dosages for monotherapy range from olanzapine 10 mg-samidorphan 10 mg to olanzapine 20 mg-samidorphan 10 mg/day.
-Dosage increases of 5 mg (olanzapine component) may be performed in no less than 24-hour intervals in patients receiving monotherapy OR in no less than weekly intervals in those receiving valproate or lithium conjunctively, based on response and tolerance.

-Acute treatment of manic or mixed episodes as monotherapy and as and adjunct to lithium or valproate
-Maintenance monotherapy treatment of bipolar disorder
-Treatment of bipolar I disorder

What other drugs will affect olanzapine and samidorphan?

If you use an opioid (prescription medication or illegal street drug) it will not work the same way while you are taking olanzapine and samidorphan. Samidorphan blocks the effects of opioids, including pain relief or feelings of well-being that can lead to opioid abuse. Trying to make an opioid work by taking large amounts can lead to overdose or death.

Do not use opioid medication during treatment with olanzapine and samidorphan and for at least 5 days after your last dose of olanzapine and samidorphan.

The opioid-blocking effects of olanzapine and samidorphan decrease slowly after you stop using this medicine, and you may be more sensitive to opioids. If you used an opioid on a regular basis and plan to start using it again after you stop olanzapine and samidorphan, you may need a lower dose of the opioid medicine.

Tell your doctor if you use any other medicine that contains olanzapine (Zyprexa, Symbyax).

Many drugs can affect olanzapine and samidorphan, and some drugs should not be used at the same time. Tell your doctor about all other medicines you use. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.