What is Olanzapine: Uses, Warnings & Interactions

Updated May 14, 2025  •  Published Dec 30, 2020

Olanzapine is a generic antipsychotic medication better known as Zyprexa. Like other antipsychotics, olanzapine affects chemicals that pass signals between nerves to reduce the symptoms of schizophrenia and relieve manic episodes in people with Bipolar I Disorder. As a second-generation antipsychotic, olanzapine is less likely to cause involuntary muscle movements than earlier antipsychotics. However, it can cause significant weight gain, one of its most common side effects.

Olanzapine overview

BRAND NAMES:

  • Zyprexa, Zyprexa Relprevv, Zyprexa Zydis

Generic Names:

  • Olanzapine

Uses:

  • Treats schizophrenia or bipolar disorder.

Therapeutic Classes:

  • Antipsychotic, multi-acting receptor-targeted antipsychotic, antidepressant augmentation agent

Forms:

  • Tablet, dissolving tablet, injection, extended-release injection

How it’s taken:

  • By mouth, injection

What is Olanzapine used for?

Olanzapine treats schizophrenia and bipolar I manic or mixed episodes. The FDA has also approved olanzapine along with the antidepressant fluoxetine to treat depressive episodes in people with bipolar disorder.

What form(s) does Olanzapine come in

  • Tablet

    • 2.5 mg

    • 5 mg

    • 7.5 mg

    • 10 mg

    • 15 mg

    • 20 mg

  • Orally disintegrating tablet

    • 5 mg

    • 10 mg

    • 15 mg

    • 20 mg

  • Injection

    • 10 mg/single-dose vial

  • Extended-release injection (olanzapine pamoate)

    • 210 mg/single-dose vial

    • 300 mg/single-dose vial

What are common Olanzapine doses?

  • For schizophrenia in adults and adolescents 13 years of age and older: 5–10 mg daily OR 150–300 mg deep intramuscular injection (Zyprexa Relprevv) every two weeks OR 400 mg deep IM injection (Zyprexa Relprevv) every four weeks

  • For manic or mixed episodes of bipolar disorder in adults and adolescents 13 years of age and older: 10–15 mg daily 

  • For agitation associated with schizophrenia or bipolar I mania: 10 mg intramuscular injection followed by other injections if necessary

Common Olanzapine prescriptions

  • OLANZapine
    30 tablets disintegrating bottle

  • OLANZapine
    10mg solution reconstituted

  • OLANZapine
    10mg tablet

  • OLANZapine
    15mg tablet

  • OLANZapine
    2.5mg tablet

  • OLANZapine
    20mg tablet

  • OLANZapine
    5mg tablet

  • OLANZapine
    7.5mg tablet

  • OLANZapine
    10mg tablet disintegrating

  • OLANZapine
    15mg tablet disintegrating

  • OLANZapine
    20mg tablet disintegrating

  • OLANZapine
    5mg tablet disintegrating

How to take Olanzapine

  • Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.

  • Please read the Medication Guide that comes packaged with this medicine before using it.

  • Olanzapine tablets and orally disintegrating tablets can be taken with food or on an empty stomach.

  • How to take olanzapine tablets:

    • Swallow the tablet whole with a glass of water.

    • Store olanzapine tablets at room temperature in a dry place protected from light and moisture.

  • How to take olanzapine orally disintegrating tablets:

    • Make sure your hands are dry before you handle the disintegrating tablet.

    • Peel back the foil from the blister pack and then remove the tablet. Do not push the tablet through the foil.

    • Immediately place the tablet in your mouth. 

    • After it has melted, swallow or take a drink of water.

    • Store olanzapine orally disintegrating tablets at room temperature in a dry place protected from light and moisture.

What to do if you miss a dose of Olanzapine

  • Take a missed dose as soon as you remember. 

  • If it is almost time for your next dose, skip the missed dose and take the next dose at its regular time. 

  • Do not take extra medicine to make up for a missed dose.

Olanzapine contraindications

  • This medicine is not right for everyone. 

  • Do not use it if you have had an allergic reaction to olanzapine.

Olanzapine warnings

  • Tell any doctor or other healthcare provider who treats you that you are taking olanzapine. 

  • The prescriber will need to schedule regular visits and blood tests to monitor the effects of olanzapine treatment. Keep all appointments.

  • Tell the doctor if you are pregnant, breastfeeding, or have:

    • Heart problems

    • A history of strokes or “mini-strokes”

    • Liver problems

    • Diabetes

    • High or low blood pressure

    • High cholesterol

    • Bowel obstruction

    • Enlarged prostate

    • Breast cancer

    • Alzheimer’s disease

    • Narrow-angle glaucoma

    • Suicidal thoughts

  • Olanzapine can cause serious side effects, including:

    • Neuroleptic malignant syndrome (NMS), a potentially life-threatening complication of antipsychotic medications

    • Weight gain

    • Changes in behavior or mood

    • Suicidal thoughts

    • High blood sugar

    • High cholesterol and fat levels

    • Low blood pressure when standing up or changing position

    • Increased risk of falls and injuries

    • Increased risk of infections

    • Seizures

    • Involuntary muscle movements of the face and body

  • This medicine may make you dizzy or drowsy, or it may cause trouble with thinking or controlling body movement. Accidental injury is a common side effect of olanzapine treatment. Do not drive or do anything that could be dangerous until you know how this medicine affects you. 

  • Olanzapine can cause lightheadedness or fainting when getting up suddenly from a lying or sitting position. To avoid this problem, stand up slowly. If you feel dizzy or faint, sit or lie down until it passes.

  • This medicine may make it more difficult for your body to cool down. Be careful to avoid becoming overheated or dehydrated during exercise or hot weather.

  • The orally dissolving tablets may contain aspartame. People with phenylketonuria could experience a potentially severe reaction to these tablets.

  • Extended-release olanzapine injections can cause a serious problem called Post-injection Delirium Sedation (PDSS) within three hours of the injection. Patients or their caregivers should discuss this risk and its symptoms before starting the injection. People receiving extended-release injections will have to stay at the clinic or hospital for at least three hours after the injection for careful monitoring.

  • Talk to a doctor if symptoms do not improve or worsen.

  • Do not suddenly stop taking doses. The prescriber will need to slowly decrease the dose before the drug can be stopped completely.

Olanzapine interactions

  • To avoid potentially hazardous drug interactions, tell the prescribing healthcare provider about all prescription drugs, over-the-counter medications, and supplements being taken.

  • Tell other healthcare providers you are using olanzapine before they prescribe new medications.

  • Do not take olanzapine tablets with other drugs that contain olanzapine, including Symbyax (olanzapine-fluoxetine) or Lybalvi (olanzapine-samidorphan).

  • Some medicines can affect how olanzapine works. Tell the prescriber if you are using:

    • Antacids

    • Carbamazepine, cimetidine, diazepam, fluoxetine, fluvoxamine, omeprazole, or rifampin

  • Olanzapine can affect how other drugs work, so tell the prescriber about using any of the following drugs:

    • Any drugs that affect the central nervous system, such as tranquilizers, sedatives, opioids, amphetamines, antidepressants, and similar drugs

    • Blood pressure medications

    • Drugs that affect heart rhythms

    • Macrolide antibiotics

    • Levodopa

  • Do not drink alcohol while you are using this medicine.

  • Avoid smoking. Tobacco may make olanzapine less effective.

Olanzapine side effects

Serious side effects

Stop taking this medicine and check with your doctor right away if you have any of the following symptoms: 

  • High fever, rigid muscles, excessive sweating, heartbeat or breathing changes, confusion

  • Rash, fever, swollen glands

Talk to a doctor if you notice any signs or symptoms of a possible serious side effect, including:

  • Thoughts of hurting yourself, suicide attempts, depressed mood, impulsive behaviors, insomnia, unusual behaviors

  • Trouble swallowing

  • Jerky muscle movement you cannot control (often in your face, tongue, or jaw)

  • Dizziness, faintness, fast or slow heartbeats when standing up

  • Seizures

  • Sweating too much, not sweating, feeling hot, feeling thirsty, dry mouth, decrease in urination

  • Feeling thirsty, feeling hungry, weakness, tiredness, frequent urination, stomach sickness, confusion

  • Eye pain, trouble seeing

  • Fever, chills, cough, sore throat, body aches

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

Less serious side effects

  • Lack of energy

  • Dry mouth

  • Weight gain

  • Increased appetite

  • Sleepiness or unusual drowsiness

  • Tremor

  • Constipation

  • Dizziness

  • Behavior changes

  • Restlessness

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