Skip to main content


Pronunciation: oh-lanz-a-peen
Generic name: Olanzapine
Brand names: Zyprexa, Zyprexa Zydis, Zyprexa Intramuscular, Zyprexa Relprevv
Dosage form: oral tablets, orally disintegrating tablets, intramuscular injection, long-acting intramuscular injection (Zyprexa Relprevv)
Drug class: Atypical antipsychotics

Medically reviewed by Carmen Pope, BPharm. Last updated on Apr 23, 2024.

What is olanzapine?

Olanzapine is an atypical antipsychotic that may be used to treat adults and adolescents aged 13 and older with schizophrenia or bipolar I disorder. For bipolar I disorder, it may be used:

For treatment-resistant depression, olanzapine is used in combination with fluoxetine (Symbyax).

Olanzapine is available as oral tablets, orally disintegrating tablets, or an injection that is given into a muscle (intramuscular [IM]). The olanzapine IM preparation is only for acute agitation associated with schizophrenia and bipolar I mania in adults.

Olanzapine may work by blocking certain receptors in the brain, notably dopamine and serotonin, although the exact way it works in schizophrenia and bipolar I disorder is unknown.

Olanzapine was FDA approved on September 30, 1996, under the brand name Zyprexa. Generic olanzapine is available.

Olanzapine side effects

Olanzapine may cause serious side effects such as an increased risk of death or stroke in elderly patients with dementia, a higher risk of suicide when taken with fluoxetine, metabolic changes, tardive dyskinesia, low blood pressure, and blood cell disorders. See the warnings below for a full list of serious side effects.

Common side effects of olanzapine that affect 5% or more people who take it include postural hypotension (a drop in blood pressure when going from a lying or sitting position to standing)

Other side effects may include increased salivation, speech disorder, forgetfulness, and the feeling of pins and needles in your limbs.

Teenagers experienced greater increases in prolactin, liver enzymes, and sleepiness, when compared with adults.

Tell your doctor about any side effect that bothers you or does not go away.

These are not all the possible side effects of olanzapine. For more information, ask your doctor or pharmacist. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.


Olanzapine may cause serious side effects, including:

May cause drowsiness and impair judgment, thinking, and motor skills. Use with caution when driving or operating machinery until you know how olanzapine affects you.

Olanzapine has not been approved for use in:

Olanzapine cost

The cost of prescription drugs varies depending on your insurance plan and which pharmacy you use. Refer to our price guide page for more information about the cost of olanzapine.

Before taking

Olanzapine may not be right for you. Before starting, tell your doctor if you have or had:

Tell your doctor if you exercise a lot or live or holiday in hot places.


Taking antipsychotic medication, such as olanzapine, in the last 3 months of pregnancy may cause breathing problems, feeding problems, or withdrawal symptoms in the newborn. If you get pregnant, tell your doctor right away but do not stop taking olanzapine without your doctor's advice.

Talk to your healthcare provider about registering with the National Pregnancy Registry for Atypical Antipsychotics. You can register by calling 1-866-961-2388 or go to 


Olanzapine passes into your 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. Talk to your doctor about the best way to feed your baby if you take olanzapine.

How should I take olanzapine?

Take olanzapine exactly as prescribed. Your doctor may need to change (adjust) the dose of olanzapine until it is right for you.

The usual starting dose for adults with:

Olanzapine tablets

Olanzapine is usually taken once a day.

Olanzapine disintegrating tablets

Olanzapine disintegrating tablets dissolve in your mouth without water.

Olanzapine IM injection

Olanzapine IM is a short-acting formulation that may be given to adults with schizophrenia or bipolar I mania if they have become agitated.

Olanzapine: Other information

You may need regular medical tests while you are taking olanzapine to check your cholesterol levels.

If you are diabetic, check your blood sugar levels regularly, because olanzapine can cause high blood sugar levels, even in people who are not diabetic.

Olanzapine may cause you to gain weight more easily. Be conscious of your weight and what you eat. Exercise regularly. Talk to your healthcare provider if you are putting on too much weight.

Call your healthcare provider if you do not think you are getting better or have any concerns about your condition while taking olanzapine.

What should I avoid while taking olanzapine?

Olanzapine can cause sleepiness and may affect your ability to make decisions, think clearly, or react quickly. You should not drive, operate heavy machinery, or do other dangerous activities until you know how it affects you.

Avoid drinking alcohol. Dangerous side effects could occur.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.

Avoid becoming overheated or dehydrated. Drink plenty of fluids, especially in hot weather and during exercise. It is easier to become dangerously overheated and dehydrated while you are taking olanzapine.

Avoid stopping olanzapine suddenly. You should never stop taking it without your doctor’s advice. When it comes time to stop olanzapine, it should be withdrawn slowly over several weeks under a doctor’s supervision. One survey reported at least 72% of people taking antipsychotics such as olanzapine experienced withdrawal symptoms.

Olanzapine withdrawal

Common symptoms of olanzapine withdrawal include nausea, headaches, dizziness, sleep disturbances, brain zaps, and psychological symptoms, such as anxiety, irritability, mood swings, and difficulty concentrating.

What happens if I miss a dose?

If you miss a dose of olanzapine, take the missed dose as soon as you remember. If it is almost time for the next dose, just skip the missed dose and take your next dose at the regular time. Do not take two doses at the same time.

What happens if I overdose?

If you take too much olanzapine, call your doctor or poison control center at 1-800-222­-1222 right away, or get emergency treatment.

Overdose symptoms may include drowsiness, agitation, aggression, slurred speech, confusion, increased heart rate, jerky or uncontrolled muscle movements, trouble breathing, or fainting.

What other drugs will affect olanzapine?

Tell your doctor about all the medicines that you take, including prescription and nonprescription medicines, vitamins, and herbal supplements. Olanzapine and some medicines may interact with each other and may not work as well, or cause possible serious side effects. Your doctor can tell you if it is safe to take olanzapine with your other medicines. Do not start or stop any medicine while taking olanzapine without talking to your doctor first. Especially tell your doctor if you take:

Anticholinergics (antimuscarinics), such as benztropine. Use with caution in patients with urinary retention, prostatic conditions, constipation, and some other conditions

Alcohol may also make side effects such as sleepiness and orthostatic hypotension worse.

Taking olanzapine with other drugs that make you sleepy or slow your breathing can cause dangerous or life-threatening side effects. Ask your doctor before using opioid medication, a sleeping pill, a muscle relaxer, or medicine for anxiety or seizures.

This is not a complete list of interactions. Talk to your healthcare provider or pharmacist for a full list of interactions.


Store olanzapine at room temperature, between 68°F to 77°F (20°C to 25°C), away from light. Keep it dry and away from moisture.

Keep out of the reach of children.


Olanzapine tablets (Zyprexa)

Active ingredient: olanzapine.

Inactive ingredients: carnauba wax, crospovidone, hydroxypropyl cellulose, hypromellose, lactose, magnesium stearate, microcrystalline cellulose, and other inactive ingredients.

Color coating: Titanium Dioxide, FD&C Blue No. 2 Aluminum Lake, or Synthetic Red Iron Oxide.

Olanzapine is available as 2.5 mg, 5 mg, 7.5 mg, 10 mg, 15 mg, and 20 mg tablets. Tablets are not scored.

Olanzapine disintegrating tablets (Zyprexa Zydis)

Active ingredient: olanzapine.

Inactive ingredients: gelatin, mannitol, aspartame, sodium methyl paraben, and sodium propylparaben.

Olanzapine Zydis orally disintegrating tablets are available as 5 mg, 10 mg, 15 mg, and 20 mg tablets. Tablets are not scored.

Olanzapine IM injection (Zyprexa)

Active ingredient: olanzapine.

Inactive ingredients: lactose monohydrate, tartaric acid, hydrochloric acid, sodium hydroxide.

Olanzapine injection is available as a 10 mg vial.


Various generic manufacturers and Eli Lilly and Company (Zyprexa).

Further information

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