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Olanzapine (Zyprexa®, Zydis®)

Summary: Olanzapine (Zyprexa®, Zyprexa Zydis®) belongs to a group of medications called “atypical antipsychotics” or “second-generation antipsychotics”, and is used in several conditions including schizophrenia, bipolar, mood/anxiety conditions and aggression.
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Olanzapine (Zyprexa®, Zyprexa Zydis®) belongs to a group of medications called  “atypical antipsychotics” or “second-generation antipsychotics”.

What is olanzapine used for?

Olanzapine may be used for several conditions such as:

  • Schizophrenia and other thought disorders
  • Bipolar disorder
  • Symptoms associated with some types of mood and anxiety disorders such as  obsessive compulsive disorder (OCD)
  • Aggression

Your doctor may be using this medication for another reason. If you are unclear why this medication is being prescribed, please ask your doctor.

How does olanzapine work?

Like other atypical antipsychotics, olanzapine affects the levels of certain chemicals in the brain called dopamine and serotonin. This has been shown to help people who have disorders like schizophrenia and bipolar disorder with their symptoms.

Olanzapine in children and adolescents

In the USA, Olanzapine is approved by the FDA for the treatment of bipolar disorder and schizophrenia.


Olanzapine has been shown in effective in various conditoins in children and adolescents, including bipolar disorder; schizophrenia and aggression in patients with autism.

How should olanzapine be taken?

Olanzapine is available in several forms, such as tablets (regular or tablets that dissolve in your mouth (called Zyprexa Zydis®)), and a short-acting injection used in cases of emergency. Olanzapine is usually taken once a day with or without food. Olanzapine should be taken at the same time each day as directed by your doctor. Try to connect it with something you do each day (like eating breakfast or brushing your teeth) so that you don’t forget.


Try to avoid alcohol while taking olanzapine.


If you are taking the dissolving tablets, (Zydis®) follow these directions. Since this medication will be prescribed in a “blister pack” (not a bottle), you have to be careful when taking the medication out of the blister.

  1. Use dry hands (wet hands can cause the medication to melt in your hands) to peel off the foil from the back of the blister before removing the tablet (rather than pushing the thin wafer through the foil).
  2. Place the tablet on your tongue. The tablet will dissolve quickly and may be swallowed with or without water. Try not to chew the tablet.

Usually, your doctor will start with a low dose of olanzapine that is best suited to your age and weight. This dose will then be slowly increased over several days or weeks based on how you respond to it. You and your doctor can then discuss the best dosage to stay on based on how you tolerate this medication (how well it helps decrease your symptoms and how you are doing with side effects).

When will olanzapine start working?

This depends on what you are using it for. Some improvements may be seen in as little as 1 to 2 weeks. However, it can sometimes take up to 6 weeks to see the full benefits of the medication. When olanzapine is working well, you may notice that your thoughts are clearer and more organized. Agitation may be decreased and hearing voices or seeing things no one else sees (hallucinations) may stop completely or happen much less. Your mood may be more settled and you may see a reduction of intense fears and worries.


It is important that you continue taking olanzapine regularly even if you are feeling well, as it can prevent symptoms from returning. If you are taking this medication to help with symptoms of mood disturbance, you may notice some changes in the first 1 to 2 weeks.


Medications like olanzapine do not work for everyone. If you are not feeling better within 6 weeks, your doctor may recommend switching you to a different medication.

How long do I have to take olanzapine?

This depends on the symptoms you have, how frequently they occur, and how long you have had them. Most people will need to take olanzapine for several months. This allows time for your symptoms to stabilize and for you to regain your functioning. Your doctor will discuss the benefits and risks of taking olanzapine with you. At this time, you can also discuss how long you might need to take this medication.


Do not increase, decrease, or stop taking this medication without discussing it with your doctor. If you stop taking olanzapine suddenly, it is possible that your symptoms may return or you may have a bad reaction.

Is olanzapine addictive?

No, olanzapine is not addictive and you will not have “cravings” for this medication like you might with nicotine or street drugs. If you and your doctor decide it is best for you to stop taking olanzapine, your doctor will explain how to safely come off this medication so you don’t feel negative effects as your body adjusts to being without it.

What are the side effects of olanzapine and what should I do if I get them?

As with most medications, side effects may occur when taking olanzapine. However, most side effects are mild and temporary. Sometimes the side effects may occur before any of the beneficial effects. It is also possible for some individuals to experience side effects that they feel are concerning or long-lasting. If this occurs, speak to your doctor about ways to manage them. On the next page are some of the more common side effects of taking this medicine. In brackets are suggested ways to lessen these effects.


Common side effects


Side effects are usually more common when starting a medication or after a dose increase. If any of these side effects is troublesome for you, please discuss them with your doctor, nurse or pharmacist.


  • Agitation (avoid caffeine from energy drinks, colas and coffee)
  • Blurred vision (usually disappears in 1-2 weeks; may need bright light or a magnifying glass when reading)
  • Constipation (increase exercise, fluids, vegetables, fruits and fiber)
  • Dizziness (try getting up slowly from a sitting or lying down position)
  • Drowsiness (try taking the dose at bedtime)
  • Dry mouth (try chewing sugarless gum, sour candies, ice chips, or popsicles)
  • Headache (try using a pain reliever like acetaminophen (plain Tylenol®))
  • Increase in hunger (avoid high calorie foods)
  • Stomach ache (try taking the medication with food)
  • Weight gain (monitor your food intake, increase your exercise)

Uncommon side effects (e.g., those that occur in less than 5% of patients)


Contact your doctor IMMEDIATELY if you have any of these side effects:

  • Fainting, feeling lightheaded or difficulties with balance
  • Fast or irregular heart beat
  • Feelings of restlessness
  • Fever or excessive sweating
  • Frequent urination accompanied by excessive thirst
  • Rash
  • Seizures
  • Shaking, stiffness or difficulty moving, muscle spasm or stiffness in your throat or tongue
  • Thoughts of hurting yourself, suicide, increased irritability/hostility or feeling worse
  • Weakness or severe muscle pain

Olanzapine is sometimes associated with a very rare side effect called “neuroleptic malignant syndrome”. The symptoms may include severe muscle stiffness, high fever, increased heart rate and blood pressure, irregular heartbeat (pulse) and sweating. Contact your doctor right away if this occurs.


On rare occasions, olanzapine and medications like it have been associated with a side effect called “tardive dyskinesia”. This is a side effect that can sometimes become permanent in patients who take antipsychotic medications. It involves involuntary movements of some muscles in the body like the lips, tongue, toes, hands and neck. Stopping the antipsychotic at the first signs of it occurring or switching to another “atypical” antipsychotic can decrease the chances of having this side effect continue.

What precautions should my doctor and I be aware of when taking olanzapine?

Tell your doctor or pharmacist if you:

  • Are lactose intolerant (olanzapine tablets contain lactose)
  • Have any allergies or have experienced a reaction to a medication.
  • Are taking or plan to start taking any other prescription or non-prescription medications (including herbal products). Some medications can interact with olanzapine, such as some sedatives. Your doctor may need to change the doses of your medications or monitor you carefully for side effects if you are taking medications that interact with olanzapine.
  • Have a history of heart disease, seizures, kidney or liver disease, a bowel obstruction, diabetes (or a family history of diabetes) or glaucoma.
  • Miss a period, are pregnant (or are planning to become pregnant) or are breast-feeding.
  • Are currently using alcohol or street drugs as these substances can decrease how well olanzapine works for you and/or make you feel drowsy.

What special instructions should I follow while using olanzapine?

  • Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check how you are responding to olanzapine, and to monitor for side effects.
  • Try to keep a healthy and well-balanced diet and exercise regularly. Some individuals who take olanzapine may gain weight due to an increase in appetite.
  • Do not allow anyone else to use your medication.

What should I do if I forget to take a dose of olanzapine?

If you take olanzapine only at bedtime and you forget to take it, skip the missed dose and continue with your regular schedule the next day. Do NOT double your next dose. If you take it more than once a day, take the missed dose as soon as possible. However, if it is almost time for your next dose (e.g., within 4 hours), skip the missed dose and continue with your regular schedule. Do NOT double your next dose.

What storage conditions are needed for olanzapine?

  • Keep this medication in the original container, stored at room temperature away from moisture and heat (e.g., not in the bathroom or kitchen).
  • Store dissolving tablets in the original sealed packaging and use immediately once opened.
  • Keep this medication out of reach and sight of children.

About this document

Special thanks to the Kelty Centre for Mental Health for permission to adapt this document. The original document was developed by health professionals of BC Mental Health and Addiction Services, and reviewed by the staff of the Kelty Mental Health Centre. French translation provided courtesy of the Ontario Centre of Excellence for Child and Youth Mental Health.

Creative Commons license

You are free to copy and distribute this material unchanged and in its entirety as long as 1) this material is not used in any way that suggests we endorse you or your use of the material, 2) this material is not used for commercial purposes (non-commercial), 3) this material is not altered in any way (no derivative works). View full license at For any other uses, please contact the original rights holder, the Kelty Mental Health Centre.


Information in this pamphlet is offered ‘as is' and is meant only to provide general information that supplements, but does not replace the information from your health provider. Always contact a qualified health professional for further information in your specific situation or circumstance.


Date Posted: May 1, 2013
Date of Last Revision: Oct 8, 2016

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