Olanzapine

Olanzapine (brand names Zyprexa, Zyprexa Zydis, Zyprexa IntraMuscular, Zyprexa Relprevv, and Weltruza) is an atypical antipsychotic that may be used to treat adults and adolescents aged 13 and older with schizophrenia or bipolar I disorder, depending on the formulation. For bipolar I disorder, it may be used:

• alone for manic or mixed episodes, or in combination with lithium or valproate
• with fluoxetine for depressive episodes in people aged 10 and older.

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

Olanzapine comes in five formulations, and they are not interchangeable. Each is used for different situations and has different administration requirements (see the formulations summary and how olanzapine is given below).

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 first FDA-approved on September 30, 1996, under the brand name Zyprexa. A once-monthly injection given under the skin, Weltruza, was approved on October 8, 2026. Generics are available for oral olanzapine formulations and the short-acting injection.

Olanzapine is available as oral tablets, orally disintegrating tablets, a short-acting injection given into a muscle, a long-acting (depot) injection given into a muscle, and a long-acting injection given under the skin. All formulations contain olanzapine, except the long-acting intramuscular injection (Zyprexa Relprevv), which contains olanzapine pamoate, a slow-release salt of the same active drug.

Oral tablets (brand Zyprexa)

• Used for schizophrenia and bipolar I disorder (see uses above). Taken every day at home.
• Generic available: Yes. Several manufacturers make generic olanzapine tablets, such as Apotex Inc., Dr. Reddy's Labs Ltd, and Zydus Pharms.

Orally disintegrating tablets (brand Zyprexa Zydis)

• Used for the same conditions as the oral tablets. A useful option for people who have trouble swallowing tablets, because it dissolves in the mouth.
• Generic available: Yes. Generic olanzapine orally disintegrating tablets are available.

Short-acting intramuscular injection (brand Zyprexa IntraMuscular)

• Used for: acute agitation associated with schizophrenia and bipolar I mania in adults only. It is given by a healthcare professional for short-term control of agitation, not for ongoing daily treatment.
• Generic available: Yes. Generic short-acting olanzapine intramuscular injection is available.

Long-acting intramuscular injection (brand Zyprexa Relprevv)

• Used for: schizophrenia in adults only. It is a depot injection given into the buttock muscle every 2 to 4 weeks by a healthcare professional to provide steady, long-lasting treatment.
• Generic available: No.
• Important: Zyprexa Relprevv carries extra safety requirements, including a mandatory 3-hour observation period after each injection and enrollment in a restricted REMS program (see the long-acting injection details under administration and the warnings section).

Long-acting subcutaneous injection (brand Weltruza)

• Used for: schizophrenia in adults only. It is an extended-release injection given under the skin of the stomach (abdomen) once a month by a healthcare professional.
• Generic available: No.
• Important: Weltruza is not interchangeable with Zyprexa Relprevv. The two products are given in different ways, on different schedules, and have different safety requirements. Unlike Zyprexa Relprevv, Weltruza is not part of a REMS program.

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

• heart problems
• seizures
• diabetes or high blood sugar levels (hyperglycemia)
• high cholesterol or triglyceride levels in your blood
• liver problems
• low or high blood pressure
• strokes or "mini-strokes," also called transient ischemic attacks (TIAs)
• Alzheimer's disease
• narrow-angle glaucoma
• enlarged prostate in men
• bowel obstruction
• phenylketonuria, because some olanzapine disintegrating tablets may contain phenylalanine
• breast cancer
• thoughts of suicide or hurting yourself
• any other medical condition
• are pregnant or plan to become pregnant
• are breastfeeding or plan to breastfeed.

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

Pregnancy

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 http://womensmentalhealth.org/clinical-and-research-programs/pregnancyregistry/

Breastfeeding

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.

All olanzapine formulations carry a Boxed warning for an increased risk of death in elderly patients with dementia-related psychosis.

The long-acting intramuscular injection (Zyprexa Relprevv) carries an additional Boxed warning for post-injection delirium/sedation syndrome (PDSS).

Increased risk of death in older adults with dementia-related psychosis

An increased risk of death, strokes, or "mini-strokes" called transient ischemic attacks (TIAs), have been reported in elderly people taking olanzapine who are confused, have memory loss, or have lost touch with reality (dementia-related psychosis). These people should not be given olanzapine.

Post-injection delirium/sedation syndrome (PDSS)

After an injection, Zyprexa Relprevv can occasionally enter the bloodstream too quickly, causing severe sleepiness (up to coma) and confusion, usually within 3 hours. Because of this risk, Zyprexa Relprevv is available only through a restricted (REMS) program and must be given in a certified healthcare setting where the patient is watched for at least 3 hours after each injection (see administration section below).

It is not known whether PDSS can happen with Weltruza, which is injected under the skin rather than into a muscle. No cases of PDSS were reported in clinical trials of Weltruza. PDSS is still listed as a serious side effect of Weltruza, so get medical help right away if you have signs such as feeling more sleepy than usual, confusion, dizziness, trouble walking or talking, or passing out after a Weltruza injection.

PDSS has not been linked to the oral tablets, orally disintegrating tablets, or short-acting injection.

Serious side effects

Olanzapine may cause the following serious side effects:

• A higher risk of suicide when olanzapine is used in combination with fluoxetine for people with depression.
• High blood sugar (hyperglycemia). This can happen if you have diabetes already or if you have never had diabetes. High blood sugar could lead to a build-up of acid in your blood due to ketones (ketoacidosis), coma, and death. Your doctor should do tests to check your blood sugar before you start taking olanzapine and during treatment. Call your doctor if you have any of these symptoms of high blood sugar (hyperglycemia) while taking olanzapine: feel very thirsty need to urinate more than usual feel very hungry feel weak or tired feel sick to your stomach feel confused or your breath smells fruity.
• High fat levels in your blood (increased cholesterol and triglycerides), especially in teenagers aged 13 to 17 or when used in combination with fluoxetine in children aged 10 to 17. Your healthcare provider should do blood tests to check your cholesterol and triglyceride levels before you start taking olanzapine and during treatment.
• Weight gain. This is very common in people who take olanzapine, especially in teenagers aged 13 to 17, or when used in combination with fluoxetine in children aged 10 to 17. Some people gain a lot of weight. You and your doctor should check your weight regularly. Talk to your doctor about ways to control weight gain, such as eating a healthy, balanced diet, and exercising.
• Neuroleptic Malignant Syndrome (NMS). This is a rare but serious side effect of antipsychotics, such as olanzapine, that may be fatal. NMS can cause death and must be treated in a hospital. Call your doctor right away if you become severely ill and have symptoms such as high fever, excessive sweating, rigid muscles, confusion, changes in your breathing, heartbeat, and blood pressure.
• Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS). This is a serious drug hypersensitivity syndrome with symptoms such as an extensive rash, fever, swollen lymph nodes, liver inflammation, and blood abnormalities. Tell your doctor immediately if you experience any of these signs.
• Tardive Dyskinesia. This condition causes persistent body movements that usually affect the face and tongue, which you cannot control. It may not go away even if you stop taking olanzapine and may start after you stop taking olanzapine. Tell your doctor if you get any body movements that you cannot control.
• Decreased blood pressure when you go from a lying or sitting position to standing. Symptoms may include dizziness, fast or slow heartbeat, or fainting.
• Falls. Olanzapine may make you sleepy or dizzy, may cause a decrease in your blood pressure when changing position (orthostatic hypotension), and can slow your thinking and motor skills, which may lead to falls that can cause fractures or other injuries.
• Increased prolactin levels in your blood (hyperprolactinemia). Olanzapine can cause a rise in the blood levels of a hormone called prolactin that may cause side effects including missed menstrual periods, a reversible reduction in fertility in females who can become pregnant, leakage of milk from the breasts, development of breasts in men, or problems with erection.
• Difficulty swallowing, which may cause food or liquid to get stuck in your lungs.
• Seizures. Tell your doctor if you have had a seizure before or if you have one during treatment with olanzapine.
• Changes in your blood cells. Your doctor will monitor your blood cell counts, especially if you have a history of significantly low white blood cell counts or drug-induced leukopenia or neutropenia.
• Problems with body temperature control. You could become very hot, for instance, when you exercise a lot or live or go on holiday in a very hot area. You need to drink water to avoid dehydration. Call your doctor right away if you become severely ill and have any of these symptoms: sweating too much or not at all, dry mouth, feeling very hot, feeling thirsty, or not being able to produce enough urine.
• 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:

• children under 13 years of age when used to treat schizophrenia or bipolar I disorder
• children under 10 years of age when used in combination with fluoxetine for depressive episodes.

The injectable formulations (the short-acting intramuscular injection and both long-acting injections, Zyprexa Relprevv and Weltruza) have not been approved for anyone under 18 years of age.

Common side effects of olanzapine that affect 5% or more of people who take it include:

• Postural hypotension (a drop in blood pressure when going from a lying or sitting position to standing)
• Constipation
• Weight gain and increased appetite
• Dizziness
• Personality disorder
• Restlessness
• Sedation
• Headache
• Abdominal pain
• Pain in the extremities
• Tiredness or lack of energy
• Dry mouth
• Tremor.

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

With the long-acting intramuscular injection (Zyprexa Relprevv), the most common side effects reported include headache, sleepiness or drowsiness, weight gain, dry mouth, diarrhea, nausea, common cold symptoms, increased appetite, vomiting, cough, back pain, and pain at the injection site.

With the long-acting subcutaneous injection (Weltruza), the most common side effects include weight gain, constipation, sleepiness, headache, and injection site reactions such as hardness, pain, redness, itching, and swelling.

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.

Always take or receive olanzapine exactly as your doctor tells you. Your doctor may need to change (adjust) the dose until it is right for you. The way olanzapine is given depends on which formulation you are prescribed.

Oral tablets (brand Zyprexa and generic olanzapine)

• Olanzapine is usually taken once a day.
• It can be taken with or without food.
• The usual starting dosage of olanzapine for adults with schizophrenia is 5 mg to 10 mg once a day.
• The usual starting dosage of olanzapine for adults with bipolar I disorder is 10 mg to 15 mg once a day.

Orally disintegrating tablets (brand Zyprexa Zydis and generic olanzapine)

Olanzapine disintegrating tablets dissolve in your mouth without water.

• Before taking it, make sure that your hands are dry.
• Open the sachet and peel back the foil on the blister. Do not push the tablet through the foil.
• When you open the blister, remove the tablet and put it into your mouth.
• The tablet will disintegrate quickly in your saliva so that you can easily swallow it with or without drinking liquid.

Short-acting intramuscular injection (brand Zyprexa IntraMuscular)

This is a short-acting injection given by a healthcare professional to adults with schizophrenia or bipolar I mania who have become agitated. It is used for short-term control of agitation, not for ongoing daily treatment.

• The usual dose is 10 mg as a single injection.
• Smaller doses (5 mg or 7.5 mg) can be given if these are more appropriate.
• A maximum of 3 doses may be given if needed, 2 to 4 hours apart.
• Your doctor will check you for low blood pressure on standing (orthostatic hypotension) before giving another dose. Tell your doctor if you feel faint or dizzy when you stand up.

Long-acting intramuscular injection (brand Zyprexa Relprevv)

This is a long-acting (depot) injection given by a healthcare professional to adults with schizophrenia. It provides steady treatment over 2 to 4 weeks per injection. Because of the risk of post-injection delirium/sedation syndrome, it has strict safety requirements that are different from every other olanzapine formulation.

• Your doctor will first make sure you tolerate oral olanzapine before starting the long-acting injection.
• It is injected deep into the muscle of your buttock (gluteus) every 2 to 4 weeks. It must never be given into a vein or under the skin.
• It is available only through a restricted program (the Zyprexa Relprevv REMS), and the prescriber, pharmacy, healthcare setting, and patient must all be enrolled.
• After each injection, you must stay at the healthcare setting and be watched by staff for at least 3 hours.
• When you leave, someone must be with you, and you should not drive or operate heavy machinery for the rest of that day.
• If you have symptoms of post-injection delirium/sedation syndrome after leaving (such as severe drowsiness, confusion, trouble talking or walking, muscle stiffness or shaking, or seizures), get medical help right away.

Long-acting subcutaneous injection (brand Weltruza)

This is an extended-release injection given by a healthcare professional to adults with schizophrenia. It is given once a month.

• If you have not taken olanzapine before, your healthcare provider will first check that you can tolerate it by giving you olanzapine by mouth.
• Your Weltruza dose is based on your daily oral olanzapine dose: 10 mg a day corresponds to Weltruza 318 mg, 15 mg a day to 425 mg, and 20 mg a day to 531 mg, once a month.
• No loading dose is needed, and you do not need to keep taking olanzapine tablets after starting Weltruza.
• It is injected under the skin (subcutaneously) of your stomach (abdomen).
• Weltruza can be given up to one week before or after your scheduled monthly date.

You may need regular medical tests while 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.

The symptoms of bipolar I disorder, treatment-resistant depression, or schizophrenia may include thoughts of suicide or of hurting yourself or others. If you have these thoughts at any time, tell your doctor or go to an emergency room right away.

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. If you receive the long-acting intramuscular injection (Zyprexa Relprevv), you should not drive or operate heavy machinery for the rest of the day after each injection.

Avoid drinking alcohol. Dangerous side effects could occur.

Avoid getting up too fast from sitting or lying down, 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 that at least 72% of people taking antipsychotics such as olanzapine experienced withdrawal symptoms.

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.

• Nearly half of the people describe these symptoms as severe, especially during the early stage of withdrawal.
• The length of time withdrawal symptoms from olanzapine last varies; some report symptoms last two weeks or less, while others experience symptoms for years. This appears to correlate with the length of time people have taken the medication.
• If you want to stop taking olanzapine, talk to your healthcare provider about the best way to come off it. This may involve slowly reducing your dose, switching to another medication that might be easier to withdraw from, or taking other medications to help with your withdrawal symptoms.

If you miss a dose of oral 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.

The injectable formulations are given by a healthcare professional, so your clinic will manage the timing of your injections. Contact your healthcare provider if you miss a scheduled injection appointment.

For Weltruza, if more than five weeks have passed since your last injection, you should receive your next dose as soon as possible, and your future monthly injections will be scheduled from that date.

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.

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 and may not work as well or may 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:

• Diazepam, lorazepam, or other benzodiazepines. This may make some side effects, such as orthostatic hypotension, worse.
• Carbamazepine, rifampin, or other medicines that can lower olanzapine levels. These may reduce the effect of olanzapine.
• Fluvoxamine or other medicines that can raise olanzapine levels. These may make side effects worse.
• Fluoxetine. This may increase the risk of suicidal thoughts and behaviors.
• Other medicines that contain olanzapine.
• Other medications that affect the brain, such as sedatives or sedating antihistamines. These can make side effects worse, especially when combined with alcohol.
• Heart medications that lower blood pressure. Olanzapine may cause an enhanced effect.
• Levodopa and dopamine agonists. Olanzapine may counteract the effects of these drugs.
• 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.

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.

Store oral olanzapine tablets and orally disintegrating tablets at room temperature, between 68°F and 77°F (20°C and 25°C), away from light. Keep them dry and away from moisture.

The injectable formulations are stored and prepared by your healthcare setting.

Keep out of the reach of children.

Active: olanzapine (the long-acting intramuscular injection, Zyprexa Relprevv, contains olanzapine pamoate).

Inactive: Depends on the manufacturer and formulation.

Olanzapine tablets (brand 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.
• Available as olanzapine 2.5 mg, 5 mg, 7.5 mg, 10 mg, 15 mg, and 20 mg tablets. Tablets are not scored.

Olanzapine disintegrating tablets (brand Zyprexa Zydis)

• Active ingredient: olanzapine.
• Inactive ingredients: gelatin, mannitol, aspartame, sodium methyl paraben, and sodium propylparaben.
• Available as olanzapine 5 mg, 10 mg, 15 mg, and 20 mg tablets. Tablets are not scored.

Olanzapine short-acting IM injection (brand Zyprexa IntraMuscular)

• Active ingredient: olanzapine.
• Inactive ingredients: lactose monohydrate, tartaric acid, hydrochloric acid, sodium hydroxide.
• Available as an olanzapine 10 mg vial.

Olanzapine long-acting IM injection (brand Zyprexa Relprevv)

• Active ingredient: olanzapine pamoate monohydrate.
• Inactive ingredients: carboxymethylcellulose sodium, mannitol, polysorbate 80, sodium hydroxide and/or hydrochloric acid for pH adjustment, and water for injection.
• Available as single-dose vials equivalent to 210 mg, 300 mg, and 405 mg olanzapine.

Olanzapine long-acting subcutaneous injection (brand Weltruza)

• Active ingredient: olanzapine.
• Inactive ingredients: poly(ethylene glycol)-co-poly(D, L-lactide) copolymers and dimethyl sulfoxide.
• Available as powder for extended-release injectable suspension in 318 mg, 425 mg, and 531 mg strengths.

Various generic manufacturers make oral olanzapine, such as Apotex Inc., Dr. Reddy's Labs Ltd, and Zydus Pharms.

Zyprexa is distributed by: H2-Pharma, LLC, Montgomery, AL 36117, USA. Licensed by: CHEPLAPHARM Registration GmbH, Weilerstr. 5e, 79540 Lörrach, Germany. CHEPLAPHARM Registration GmbH under the license of CHEPLAPHARM Schweiz GmbH.

Zyprexa Relprevv is distributed by H2-Pharma, LLC, Montgomery, AL, USA. Licensed by CHEPLAPHARM Registration GmbH, Lörrach, Germany, which holds the Zyprexa Relprevv REMS. For more information about Zyprexa Relprevv, call 1-866-770-9010.

Weltruza is manufactured for Teva Neuroscience, Inc., Parsippany, NJ 07054. For more information about Weltruza, call 1-888-483-8279.