Pronunciation: zy-PREX-a REL-prev
Generic name: olanzapine (as olanzapine pamoate monohydrate)
Dosage form: extended-release injectable suspension (long-acting intramuscular injection)
Drug class: Atypical antipsychotics

Medically reviewed by Carmen Pope, Senior Medical Editor, B. Pharm. Last updated on Oct 5, 2026.

What is Zyprexa Relprevv?

Zyprexa Relprevv is a long-acting intramuscular injection containing the atypical antipsychotic olanzapine that is used to treat schizophrenia in adults. It is given by a healthcare provider as a deep injection into the buttock muscle every 2 to 4 weeks, and slowly releases olanzapine. Because of this, it is a maintenance treatment taken on a regular schedule, not a one-off injection for sudden agitation.

The exact way olanzapine works is not fully understood, but its effect in schizophrenia is thought to come from blocking two brain chemical receptors, dopamine and serotonin (5-HT2).

Olanzapine was first approved by the FDA in 1996. The long-acting Zyprexa Relprevv injection has been available in the U.S. since December, 2009 and is supplied only through a restricted program called the Zyprexa Relprevv REMS.

Zyprexa Relprevv is not approved for treating psychosis related to dementia in older adults.

Warnings

Zyprexa Relprevv has a Boxed Warning, the FDA's most serious warning, for two risks: Post-injection delirium/sedation syndrome (PDSS) and increased risk of death in older adults with dementia-related psychosis.

Post-injection delirium/sedation syndrome (PDSS)

After each injection, some of the medicine can enter the bloodstream too quickly and cause symptoms that look like an olanzapine overdose, including severe drowsiness (up to and including coma) and delirium (confusion, disorientation, agitation, trouble speaking or walking). Because of this risk:

• Zyprexa Relprevv can only be given in a certified healthcare setting that has emergency services available.
• You must be watched by a healthcare professional for at least 3 hours after every injection.
• Someone must be with you when you leave the facility, and you should not drive or operate machinery for the rest of that day.
• The risk is the same with each injection, so it adds up over time (the more injections you receive, the more chances there are for an event to happen).

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

Older adults with dementia-related psychosis who are treated with antipsychotic medicines have a higher risk of death and of stroke or "mini-stroke" (transient ischemic attack). Zyprexa Relprevv is not approved for this use.

Because of the PDSS risk, Zyprexa Relprevv is available only through the Zyprexa Relprevv REMS program. The prescriber, the pharmacy, the healthcare setting, and the patient must all be enrolled before treatment can be given. To enroll or for more information, call 1-877-772-9390.

Zyprexa Relprevv side effects

Common side effects

The most common side effects of Zyprexa Relprevv include:

• headache
• sleepiness or drowsiness (sedation)
• weight gain
• dry mouth
• diarrhea
• nausea and vomiting
• symptoms of the common cold
• increased appetite
• cough
• back pain
• Pain where the injection was given.

Serious side effects

Zyprexa Relprevv may cause serious side effects. Tell your doctor or get medical help right away if you have any of the following:

• Post-injection delirium/sedation syndrome (PDSS). See the Warnings section above. Get medical help or go to an emergency room right away if, after leaving the clinic, you feel very sleepy, dizzy, confused or disoriented, have trouble talking or walking, feel weak, or have stiff or shaking muscles, higher blood pressure, or a seizure.
• High blood sugar (hyperglycemia). This can happen whether or not you already have diabetes, and in serious cases can lead to a build-up of acid in the blood (ketoacidosis), coma, or death. Your doctor will check your blood sugar before and during treatment. Tell your doctor right away if you feel very thirsty, need to urinate more than usual, feel very hungry, feel weak or tired, feel sick to your stomach, or your breath smells fruity.
• High fat levels in the blood (high cholesterol and triglycerides). These increases can happen without any symptoms and are more likely in teenagers aged 13 to 17. Your doctor will check your levels before and during treatment.
• Weight gain. Weight gain is very common and can be significant. It is more likely, and tends to be greater, in teenagers aged 13 to 17. You and your doctor should check your weight regularly.
• Neuroleptic malignant syndrome (NMS). This is a rare but life-threatening reaction. Call your doctor right away or get emergency help if you have high fever, heavy sweating, stiff muscles, confusion, or changes in your breathing, heartbeat, and blood pressure.
• Drug reaction with eosinophilia and systemic symptoms (DRESS). This can include rash, fever, swollen glands, and involvement of internal organs such as the liver, kidney, lung, or heart. DRESS can be fatal, so tell your doctor immediately if you have these signs.
• Tardive dyskinesia. This causes uncontrolled body movements, usually of the face and tongue. It may not go away even after stopping treatment, and can start after treatment ends.
• Low blood pressure when standing up (orthostatic hypotension), with dizziness, a fast or slow heartbeat, or fainting. Change positions slowly and lie down if you feel dizzy or faint.
• Falls. Drowsiness, low blood pressure, and problems with balance may lead to falls, fractures, or other injuries.
• Low white blood cell counts (leukopenia, neutropenia, agranulocytosis), which can increase the risk of infection. Tell your doctor if you develop a fever or other signs of infection.
• Difficulty swallowing (dysphagia), which can cause food or liquid to get into the lungs.
• Seizures.
• Problems controlling body temperature. You may become very hot, especially with heavy exercise or in hot places. Drink water to avoid dehydration and call your doctor right away if you sweat too much or not at all, have a dry mouth, feel very hot or thirsty, or cannot urinate.
• Increased prolactin levels (hyperprolactinemia), which may cause missed periods, breast enlargement or discharge, or sexual problems.

It is not known if Zyprexa Relprevv is safe and effective in children under 18 years of age.

Tell your doctor about any side effect that bothers you or that does not go away. These are not all the possible side effects of Zyprexa Relprevv. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Before receiving Zyprexa Relprevv

You should not receive Zyprexa Relprevv if you are allergic to olanzapine.

Before starting Zyprexa Relprevv, tell your doctor about all of your medical conditions, including if you have or have had:

• heart problems, or high or low blood pressure
• a stroke or "mini-stroke" (transient ischemic attack)
• diabetes or high blood sugar
• high cholesterol or triglyceride levels
• liver problems
• seizures
• Alzheimer's disease or dementia
• an enlarged prostate
• bowel problems or a bowel obstruction
• narrow-angle glaucoma
• breast cancer
• low white blood cell counts
• thoughts of suicide or of hurting yourself.

Tell your doctor if you exercise a lot or are often in hot places, and tell your doctor about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Do not start or stop any medicine while receiving Zyprexa Relprevv without talking to your doctor first.

The symptoms of 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.

Pregnancy

Tell your doctor if you are pregnant or plan to become pregnant. Babies exposed to antipsychotic medicines during the third trimester of pregnancy can have muscle stiffness or shakiness, tremor, sleepiness, breathing problems, feeding problems, or withdrawal symptoms after birth. If you become pregnant during treatment, tell your doctor and ask about the National Pregnancy Registry for Atypical Antipsychotics (1-866-961-2388).

Breastfeeding

Olanzapine passes into breast milk. Babies who are breastfed during treatment should be watched for excess sleepiness, irritability, poor feeding, and tremors or abnormal muscle movements. Talk to your doctor about the best way to feed your baby if you receive Zyprexa Relprevv.

Zyprexa Relprevv may affect fertility in females of reproductive potential by raising prolactin levels; this effect is reversible.

How is Zyprexa Relprevv given?

• Zyprexa Relprevv is given by a healthcare provider as a deep injection into the muscle of the buttock (gluteal muscle). It must never be given into a vein or under the skin.
• Before your first injection, your doctor will usually have you take oral olanzapine first to make sure you tolerate it.
• The injection is given every 2 to 4 weeks, at a dose that matches your oral olanzapine dose. Effective doses range from 150 mg to 300 mg every 2 weeks, or 405 mg every 4 weeks.
• After each injection, you must stay in the certified healthcare setting and be watched for at least 3 hours for signs of PDSS. Someone must be with you when you leave.
• You should not drive or operate heavy machinery for the rest of the day after each injection.

Your doctor will decide how long you need treatment. Do not stop treatment without talking to your doctor.

What happens if I miss a dose?

Because Zyprexa Relprevv is given by a healthcare provider every 2 to 4 weeks, missed doses are unlikely. If you miss a scheduled appointment, call your clinic right away to reschedule. Do not wait until your next planned appointment.

Related/similar drugs

What happens if I overdose?

Zyprexa Relprevv is given by a healthcare professional in a certified setting, so an accidental overdose is unlikely. However, post-injection delirium/sedation syndrome can cause symptoms similar to an overdose, which is why you are watched for at least 3 hours after each injection. There is no specific antidote to olanzapine; treatment is supportive.

What should I avoid while receiving Zyprexa Relprevv?

• Do not drink alcohol. Alcohol can increase drowsiness and other dangerous side effects.
• Do not drive or operate heavy machinery for the rest of the day after each injection, and not at all until you know how Zyprexa Relprevv affects you.
• Get up slowly from sitting or lying down, because you may feel dizzy and fall.
• Avoid getting overheated or dehydrated, especially during exercise or in hot weather.

What other drugs will affect Zyprexa Relprevv?

Tell your doctor about all the medicines you take. Some interactions include:

• Medicines that cause drowsiness or slow breathing (opioids, sleeping pills, muscle relaxers, and medicines for anxiety or seizures), plus alcohol, can cause dangerous or life-threatening effects. Diazepam and alcohol can also add to the drop in blood pressure caused by Zyprexa Relprevv.
• Fluvoxamine can raise olanzapine levels in the blood, so a lower dose may be needed.
• Carbamazepine, omeprazole, and rifampin, and cigarette smoking can lower olanzapine levels.
• Anticholinergic medicines can increase the risk of severe bowel and heat-related side effects.
• Blood pressure medicines may have a stronger effect (greater drop in blood pressure).
• Levodopa and dopamine agonists may not work as well.
• Avoid taking Zyprexa Relprevv with other olanzapine-containing medicines, such as Zyprexa or Symbyax (olanzapine/fluoxetine).

Other prescription and over-the-counter medicines, vitamins, and herbal products may also interact. Tell your doctor about any medicine you start or stop.

Ingredients

Active ingredient: olanzapine (as olanzapine pamoate monohydrate)

Inactive ingredients (diluent): carboxymethylcellulose sodium, mannitol, polysorbate 80, sodium hydroxide and/or hydrochloric acid for pH adjustment, and water for injection.

Manufacturer

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.

Common questions about Zyprexa Relprevv

Further information

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

Medical Disclaimer