Sounds like 'oh-LAN-za-peen'

Easy-to-read medicine information about olanzapine – what it is, how to take olanzapine safely and possible side effects.

Type of medicine Also called
  • Antipsychotic
  • Belongs to a group of medicines known as atypical antipsychotics 
  • Olanzine®
  • Zyprexa®
  • Zypine®
Oral disintegrating tablet
  • Zyprexa Zydis®
  • Zypine ODT ® 
  • Zyprexa Relprevv® 

What is olanzapine?

Olanzapine is used to treat some types of mental illness such as schizophrenia and bipolar disorder (manic depression). It does not cure these conditions, but is used to help ease the symptoms and help you on your recovery path. It can help improve symptoms such as extreme mood swings of 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 medication. 

In New Zealand, olanzapine is available in different forms of tablets, such as standard tablets, oral disintegrating tablets, and wafers. It is also available 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 tablets are different for different people, depending on your condition and your response to the medication. Doses 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 medication.  
  • 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.

How to take olanzapine

  • Olanzapine is available in different forms of tablets: 
    • Standard tablets: swallow these tablets with a glass of water. If you have problems swallowing tablets, talk to your doctor about changing to the oral disintegrating tablets, or wafers. 
    • Oral disintegrating tablets and wafers: these tablets dissolve in your mouth. Put the tablet on your tongue, let it dissolve, then swallow. Or, you can dissolve the oral dispersible tablet by stirring it into a small glass of any of these drinks: water, orange or apple juice, milk or coffee but not cola.
  • 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. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not 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.
  • Do not stop taking olanzapine suddenly as your symptoms may return if stopped too early; speak to your doctor or nurse before stopping.

Precautions – before starting olanzapine

  • Do you have any heart problems?
  • Do you have Parkinson’s Disease or epilepsy?
  • Do you have diabetes or problems with high cholesterol?
  • Have you had a stroke or blood clot?
  • Do you smoke? Or have you just stopped smoking?
  • Do you have problems with your liver or kidneys?
  • Are you pregnant or breastfeeding?
  • Are you taking any other medicines, including medicines you can buy without a prescription, such as herbal and complementary medicines?

If any of these apply, it’s important that you tell your doctor or pharmacist before you start olanzapine. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care, that your pharmacist will tell you about.

Precautions – while taking olanzapine

  • Alcohol: avoid alcohol while you are taking olanzapine, especially when you first start treatment. Drinking alcohol while taking olanzapine can cause drowsiness and affect concentration, putting you at risk of falls and other accidents. It can also cause agitation, aggression and forgetfulness. If you do drink alcohol, drink only small amounts and see how you feel. Do not stop taking your medication.
  • Weight: let your doctor know if you notice that you are putting on a lot of weight.
  • Blood tests and other monitoring: before starting olanzapine or before starting any new medicines while you are taking olanzapine, you will need blood tests and other monitoring. Olanzapine may cause changes in your blood glucose level, your cholesterol level and in your heart function. To keep an eye out for these effects, your doctor will check your physical health. You will have your weight measured regularly. You may also need to have blood tests to check your kidneys, liver, cholesterol and glucose levels. You may also have your blood pressure measured and an ECG test to check your heart rate.

Possible side effects

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

Side effects What should I do?
  • Feeling sleepy, drowsy or tired
  • It can last a few hours after the dose
  • Don’t drive or operate machinery
  • Ask your doctor if you can take your medicine at a different time
  • Avoid drinking alcohol
  • Tell your doctor if troublesome
  • Feeling dizzy
  • This usually only happens when you start your medication
  • It should wear off in a few weeks
  • Try not to stand up too quickly. You are at risk of falls
  • If you feel dizzy, don't drive
  • Weight gain
  • A diet full of vegetables and fibre may help prevent weight gain
  • Limit sugary or fatty foods
  • Exercise regularly
  • Speak with your doctor if you are putting on weight 
  • Dry mouth
  • Suck sugar-free lollies or gum
  • Constipation
  • Ask your doctor to prescribe a suitable laxative, which you need to take on a regular basis
  • Eat more fruit, vegetables, brown bread, bran-based breakfast cereals and drink plenty of water
  • Signs of diabetes such as you may lose weight, pass lots of urine, and feel thirsty and hungry all the time.
  • Tell your doctor if you get these symptoms. You can then have some simple tests to see if you are developing diabetes


Olanzapine interacts with a number of important medications and herbal supplements so check with your doctor or pharmacist before starting olanzapine or before starting any new medicines.

Learn more

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

Medsafe Consumer Information (NZ): Zypine, Zyprexa
Patient Info, UK: Olanzapine


  1. Olanzapine New Zealand Formulary
  2. Antipsychotic drugs New Zealand Formulary
  3. Prescribing atypical antipsychotics in general practice BPAC, 2011
  4. Managing patients with dementia: What is the role of antipsychotics? BPAC, 2013
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 04 Mar 2018