Olanzapine Oral / IM (Zyprexa®)

Author: OncoLink Team
Last Reviewed: July 20, 2022

Pronounce: oh-LANZ-a-peen

Classification: Atypical antipsychotic

About: Olanzapine Oral / IM (Zyprexa®)

Olanzapine is an antipsychotic medication approved for the treatment of schizophrenia, bipolar I disorder, and depression that is resistant to other treatments. Olanzapine, given in lower doses than that used to treat mood disorders and when given with other anti-nausea medications, can also be used to treat nausea and vomiting caused by cancer treatments. Olanzapine targets receptors in the brain that have been linked to nausea and vomiting. This medication sheet will focus on the use of olanzapine as an anti-nausea (antiemetic) medication.

How this Medication Comes

This medication comes in oral tablets, orally disintegrating tablets, and as an intramuscular (IM) injection. When using olanzapine to prevent nausea and vomiting due to cancer treatments, it is given orally (by mouth).

How to take Olanzapine

This medication is usually given once daily, with or without food. If you are taking the orally disintegrating tablet version, peel back the foil on the blister pack (do not push tablet through the foil) and remove it from the blister pack with dry hands. The whole disintegrating tablet should be placed on the tongue and allowed to disintegrate (melt or dissolve) without chewing or crushing it. Once it has disintegrated you should swallow the saliva in your mouth. The oral tablet can be taken with or without food.

The dose and how often you take olanzapine will depend on the cancer treatment you are getting. Most times, olanzapine is given for four days while you are receiving treatment. It is often given with 3 or 4 other medications used to prevent or treat nausea and vomiting. Ask your care team if olanzapine will be a part of your treatment plan and how/when you should take it.

Tell your provider about any medications or supplements you take. Olanzapine can interact with other medications and supplements, including buprenorphine, carbamazepine, diazepam, fluvoxamine, levodopa/dopamine agonists, lorazepam, metoclopramide, and medications that lower blood pressure, among others. If you take any medications that affect the central nervous system (CNS), be sure to tell your care team before taking olanzapine.

You should not drink alcohol while taking olanzapine. You should not drive a car or operate heavy machinery until you know how olanzapine affects you.

Storage and Handling

Store this medication in the original container. For tablets and orally disintegrating formulations, store at room temperature. Keep this medication out of reach of children and pets.

Where do I get this medication?

This medication is available through retail/mail order pharmacy.  Your oncology team will work with your prescription drug plan to identify an in-network retail/mail order pharmacy for medication distribution.  You can work with your provider’s office if this medication needs a prior authorization.

Insurance Information

Olanzapine may be covered under your prescription drug plan. Patient assistance may be available to qualifying individuals without prescription drug coverage.  Co-pay cards, which reduce the patient co-pay responsibility for eligible commercially (non-government sponsored) insured patients may also be available. Your care team can help you find these resources if they are available. 

Possible Side Effects of Olanzapine

This medication is given to manage and/or prevent side effects of your cancer treatment. If you are having side effects from this medication, you should talk to your team about if this medication is necessary to your treatment or if there are other options to help manage the side effect this medication is treating. These are some of the most common side effects:

Increased Risk in Elderly Patients with Dementia

Elderly patients who have a history of dementia should not take olanzapine. These patients have an increased risk of death and heart problems, including blood clots and stroke. Symptoms can include: swelling, redness or pain in an extremity, chest pain or pressure, pain in your arm, back, neck or jaw, shortness of breath, numbness or weakness on one side of the body, trouble talking, confusion or mental status changes. If you experience any of these symptoms, you should contact your oncology care team immediately or go to an emergency room.

Central Nervous System (CNS) Effects

Because of how this medication works and its effects on neurotransmitters in the brain, olanzapine may cause drowsiness, fatigue, sedation, dizziness, and weakness. If these effects make it hard to carry out daily life, talk with your provider. Again, you should not drink alcohol while taking olanzapine. You should not drive a car or operate heavy machinery until you know how olanzapine affects you.

Xerostomia (Dry Mouth)

This medication can cause xerostomia, also known as dry mouth. Xerostomia can be uncomfortable and can affect your speech, swallowing, and dental health. Ways to manage this side effect include:

  • Perform frequent oral hygiene with toothpaste containing fluoride.
  • Floss once a day, if your care team says you can.
  • Chew sugar-free gum or suck on sugar-free candy to stimulate saliva production.
  • Rinse your mouth frequently to keep the mouth moist.
  • Speak to your providers about over the counter and prescription gels and rinses that act as saliva replacement.

Speak to your provider if this side effect continues to be a problem.

Increased Appetite

Olanzapine may increase your appetite. Because you will likely be taking olanzapine only for a few days during treatment, weight gain should not be an issue. With prolonged chronic use, you may gain weight. Talk with your healthcare team if you have concerns about this.

Hypotension (low blood pressure)

Olanzapine can lower your blood pressure, especially when going from lying or sitting to standing. Call your care team if you feel dizzy or lightheaded. Take your time when going from a lying to a sitting and standing position.Your healthcare team may suggest taking your dose in the evenings to lower this risk. Confirm what time of day your prescriber wants you to take the medication.

Less common, but important side effects can include:

  • High blood sugar: This medication can cause high blood sugar levels in patients with and without diabetes. Your oncology care team will monitor your blood sugar. If you have increased thirst, urination or hunger, blurry vision, headaches or your breath smells like fruit, notify your healthcare team. Diabetics should monitor their blood sugar closely and report higher sugar levels to the healthcare team.
  • Increased blood lipid levels:This medication can cause higher levels of lipids (fats) in your blood. Your provider will monitor these levels with blood work.
  • Seizures: Tell your provider if you have a history of seizures, or if you take medication to prevent seizures.
  • Tardive Dyskinesia:In rare cases, this medication can cause tardive dyskinesia. This can lead to abnormal muscle movements, often in the face, including grimacing, sticking out the tongue, and smacking of the lips. Alert your healthcare team immediately if you notice or develop any of these symptoms.
  • Neuroleptic Malignant Syndrome: This side effects can cause high fever, stiff muscles, problems thinking, fast heart rate, and increased sweating. This side effect is rare but can be serious. Contact your provider if you have any symptoms of neuroleptic malignant syndrome.

Reproductive Concerns

You should consult with your provider before becoming pregnant or fathering a child while on this medication. You should consult with your healthcare team before breastfeeding while receiving this medication. Olanzapine may impair fertility in men and women with reproductive potential. Talk to your provider about these risks.