Sounds like 'oh-LAN-za-peen'

Key points about olanzapine

  • Olanzapine is used to treat some types of mental illness such as bipolar disorder and schizophrenia.
  • Olanzapine is also called Zyprexa or Zypine.
  • Find out how to take it safely and possible side effects.
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Olanzapine is used to treat schizophrenia and bipolar disorder and associated agitation. It doesn't cure these conditions, but is used to help ease the symptoms and help you on your recovery path. 

  • It can help improve symptoms such mania with bipolar disorder, the experience of hearing voices (hallucinations), ideas that distress you and don't seem to be based in reality (delusions), and difficulty in thinking clearly (thought disorder). 
  • Olanzapine belongs to a group of medicines called antipsychotics. Read more about antipsychotic medicines and how they work. 

In Aotearoa New Zealand, olanzapine is available as tablets and can also be given as an injection. The long-acting or depot injection is an option when your symptoms have settled after taking tablets. Read more about depot antipsychotics. 

  • The dose of olanzapine is different for different people, depending on your condition and your response to the medicine.
  • Doses of tablets range from 5 milligrams to 20 milligrams a day.
  • Your doctor will start you on a low dose and increase it slowly as your body gets used to the medicine.  
  • Always take your olanzapine exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much olanzapine to take, how often to take it and any special instructions.

Olanzapine tablets are available in 2 different forms – tablets or oral disintegrating tablets (also called ODTs).  


  • Swallow the tablets with a glass of water. Don't halve or crush the tablets.

Oral disintegrating tablets

  • These tablets break easily, so you should handle them carefully. Don't handle them with wet hands as they may break up.
  • The tablets dissolve in your mouth. Put the tablet on your tongue, let it dissolve, then swallow.
  • You can also dissolve the tablet by stirring it into a small glass of water or other suitable non-alcoholic drink (except cola). Drink it straightaway. 

Olanzapine tablets are usually taken once a day. Try to take your olanzapine dose at the same time each day.

  • You can take olanzapine with or without food.
  • If you forget to take your dose, take it as soon as you remember that day. Bu, if it is nearly time for your next dose, just take the next dose at the right time. Don't take double the dose.
  • Keep taking olanzapine every day. It usually takes a few weeks to start working and it can take several months before you feel the full benefits.
  • Don't stop taking olanzapine suddenly as your symptoms may return if stopped too early. Talk to your doctor or nurse before stopping.

Here are some things to know when you're taking olanzapine. Other things may be important as well, so ask your healthcare provider what you should know about.

  • Avoid alcohol while you are taking olanzapine, especially when you first start treatment. Alcohol can increase your risk of side effects such as dizziness and drowsiness. 
  • Olanzapine can interact with other medicines. Tell your doctor or pharmacist about all medicines you are taking including over the counter medicines, herbal and complementary medicines or recreational drugs.
  • Olanzapine may cause changes in your blood glucose level, cholesterol level and heart function. Your doctor will check your physical health – you may need to have your weight and blood pressure (BP) measured regularly. You may also need blood tests to check your kidneys, liver, cholesterol and glucose levels.
  • Olanzapine is best avoided for people with certain medical conditions such as Parkinson’s disease, epilepsy, depression, dementia and diabetes. Contact your doctor if you have or develop any of these conditions while taking it.
  • Contact your doctor if you are pregnant or planning a pregnancy or if you are breastfeeding.
  • Olanzapine can make your skin more sensitive to sunlight. Protect yourself, even on a bright but cloudy day; use sunscreen and wear a hat. Don't use sunbeds.
  • Talk to your doctor before starting or stopping smoking while you are taking olanzapine as your dose may need to be adjusted.

Like all medicines, olanzapine can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Feeling sleepy, drowsy or tired
  • Dizziness
  • This is quite common especially when you first start taking olanzapine.
  • Don’t drive or operate machinery until you know how this medicine affects you.
  • Avoid drinking alcohol – it makes the drowsiness worse. 
  • These effects puts you at increased risk of falls, especially if you are elderly.
  • Tell your doctor if these bother you.
  • Increased appetite
  • Weight gain
  • This is common when taking olanzapine.
  • Eat plenty of vegetables and fibre and limit sugary or fatty foods.
  • Exercise regularly.
  • Talk to your doctor if you're concerned.
  • Read more about medicines and weight gain.
  • Constipation
  • Ask your doctor to prescribe a suitable laxative, which you will need to take on a regular basis.
  • Eat more fruit, vegetables, brown bread, bran-based breakfast cereals and drink plenty of water.
  • Read more about medicines and constipation.
  • Sexual problems such as low libido and erectile dysfunction
  •  Talk to your doctor if this is a problem.
  • Sweating, high temperature, confusion, disorientation
  • Contact your doctor immediately, especially if you are taking higher doses.
Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product.(external link)

The following links have more information on olanzapine. Be aware that websites from other countries may contain information that differs from New Zealand recommendations. 

Med-ucation medication benefits & side effects(external link) Talking Minds, NZ 
Medsafe Consumer Information (NZ): Zypine(external link), Zyprexa(external link)
Patient Info, UK: Olanzapine(external link)


5 questions to ask about your medications(external link) Health Quality and Safety Commission, NZ, 2019 English(external link), te reo Māori(external link)


  1. Olanzapine(external link) New Zealand Formulary
  2. Antipsychotic drugs(external link) New Zealand Formulary

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist, Auckland

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