What does it do?

Olanzapine is an antipyschotic used to treat some mental health problems such as schizophrenia and psychosis.

A person diagnosed with schizophrenia or psychosis may hear voices talking to them or about them. They may also become suspicious or paranoid. Some people also have problems with their thinking and feel that other people can read their thoughts. These are called “positive symptoms”. Olanzapine can help to relieve these symptoms.

Many people with schizophrenia also experience “negative symptoms”. They feel tired and lacking in energy and may become quite inactive and withdrawn. Olanzapine may help relieve these symptoms as well.

Olanzapine is also used for treating mania and as a mood stabiliser in bipolar affective disorder.

Olanzapine is sometimes prescribed for people who have had side effects such as strange movements and shaking with older types of antipsychotics. Olanzapine does not usually cause these effects. Older antipsychotics may also increase levels of the hormone prolactin which can lead to either less interest in sex or problems having sex. Olanzapine does not usually increase prolactin.

Before you start

• Tell your doctor if you have heart, liver, bowel, bladder or prostate problems.
• Tell your doctor if you have diabetes, Parkinson’s disease, angle-closure glaucoma, have ever had a seizure, blood clot, stroke or ‘mini-stroke’, or if you have experienced strange body movements with another medicine.
• Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.

How should you take it?

Take olanzapine regularly as directed with a glass of water.
Wafers or orodispersible tablets: Place on your tongue to dissolve before swallowing. You can also dissolve them in a glass of water.

Look at the label on your medicine. It should have all the necessary instructions on it. Follow these directions carefully. Never be tempted to change the dose yourself. If you have any questions, speak to your doctor, pharmacist, case manager or nurse.

When you feel better, can you stop taking it?

No. If you stop taking olanzapine your original symptoms may return, but this may not be for three to six months after you stop the medicine.

You and your doctor should decide together when you can come off it. Most people need to be on olanzapine for quite a long time, sometimes years. This is not thought to be harmful. Olanzapine is not addictive.

What if you forget a dose?

If it is nearly time for your next dose, skip the missed dose and take your next dose at the usual time. Otherwise, take the missed dose as soon as you remember. Do not take two doses at the same time.

Can you take other medicines?

Some medicines available without a prescription may react with olanzapine including:

• some antihistamines or anti-nausea medicines such as promethazine (e.g. Phenergan®), hyoscine (e.g. Scopoderm®), meclozine (e.g. Sea-legs®)

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products (e.g. kava, St John's wort) or recreational drugs.

What side effects might you notice?

Side Effects	Recommended action
Lightheaded or dizzy after standing up	Stand up slowly. If it continues, or is severe, tell your doctor
Drowsiness	Avoid tasks you need to be alert for such as driving or using machines. Ask your doctor if you can take it at a different time of the day.
Weight gain	Eat a healthy diet full of vegetables and fibre. Keep active (e.g. walk regularly). Avoid fatty foods like chocolate and chips and high sugar foods such as cakes, sweets and fizzy drinks. Ask to see a dietitian if you need help with food choices.
Constipation	Eat more fibre (e.g. bran and vegetables). Drink plenty of fluid. Do more walking. A mild laxative from a pharmacy might help.
Dry mouth	Sip water regularly. Brush your teeth twice a day with fluoride toothpaste. Avoid sugary drinks and snacks between meals. Try sugar free chewing gum to stimulate saliva or discuss using an oral lubricant with your pharmacist or dentist.
Swollen feet or legs Less interest in, or trouble having sex	Discuss this with your doctor when you next meet.
More sensitive to sunlight (sunburn or rash)	Protect yourself from too much sunlight. Always cover up and apply a thick layer of broad spectrum sunscreen (at least SPF 30) when outside. Do not use sunbeds.
Reduced number of blood cells that fight infections in your body - symptoms include: fever, chills, sore throat or generally feeling unwell	This can be picked up from a blood test. Always tell your doctor or carer if you feel ill in any way.

If you notice any other effects, discuss them with your doctor or pharmacist.

What about alcohol or marijuana?

It’s best not to drink alcohol, use marijuana or other recreational drugs when you take olanzapine. Using these together can make you sleepy. They can also make olanzapine work less well and cause more side effects, like making you clumsy. This can lead to falls or accidents. Using recreational drugs can also make your psychosis worse, especially if you use a lot.

Once you are used to taking olanzapine, you can sometimes drink alcohol in small amounts without harming yourself. If you want a drink, try one glass of your usual drink and see how you feel. If it doesn’t make you feel sleepy or clumsy, small amounts are probably okay. Be careful, because alcohol affects everyone differently, especially when you are taking medicines.

Many road accidents happen when people mix alcohol, marijuana, or other recreational drugs with medicines like olanzapine. Make a plan for getting home safely if you choose to drink or use drugs. Don’t stop taking olanzapine just because you want a joint, a drink, or a party pill on the weekend.

What is the metabolic syndrome?

Antipsychotics can cause something called the metabolic syndrome. This is a combination of weight gain, raised cholesterol and raised blood sugars. Some antipsychotics are more likely to cause the metabolic syndrome than others.

When you start an antipsychotic, your weight, height and waist size will be measured and a number of blood tests will also be completed. These will be repeated several times during the first year that you are on an antipsychotic to ensure that you remain healthy. It is important when you start an antipsychotic that you eat a healthy diet and that you do some regular exercise.

Talk to your case manager or doctor for advice about this. They may also offer to refer you to a dietitian.

Other information:

• Smoking can change the effect of olanzapine. Tell your doctor if you give up, cut down or start smoking.