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Olanzapine (long-acting injection)

oh-lan-zah-peen

What does it do?

Olanzapine is used to treat and prevent some mental health problems such as schizophrenia and bipolar disorder.

How is it given?

Olanzapine injection is given into a muscle by a health professional, usually every two to four weeks.
Very rarely, olanzapine can cause extreme sleepiness. Because of this, you will need to stay in the hospital or clinic for at least two hours after your injection.

What if you forget a dose?

If you miss an appointment for your injection, contact your health professional as soon as possible.

Can you take other medicines?

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

  • some antihistamines (may be in anti-allergy, anti-nausea and cough/cold medicines)
  • anti-nausea medicines (e.g. prochlorperazine, hyoscine (e.g. Scopoderm TTS®), 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. St John's wort, kava) or recreational drugs.

What side effects might you notice?

Side EffectsRecommended action

Fever, stiffness, sweating, confusion

Feeling restless, strange or uncontrolled movements, tremor

Fast or irregular heartbeat, chest pain, fainting

Symptoms of a blood clot including: sudden shortness of breath, swelling or pain in one leg

Seizures

Prolonged erection (longer than four hours)

Tell your doctor immediately

Drowsiness, dizziness, tiredness or weakness, headache, anxiety

Weight gain

Dry mouth, blurred vision, constipation, trouble peeing

Stomach upset

Peeing when you don’t want to

Changes in periods

Sore or enlarged breasts, breastmilk production

Less interest in sex, impotence

Pain, tenderness or redness at injection site

Tell your doctor if troublesome

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

Other information:

  • Tell your doctor if you have heart, liver, bowel, bladder, prostate or eye (e.g. glaucoma) problems.
  • Tell your doctor if you have diabetes, Parkinson’s disease, 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.
  • Your doctor may do a heart test (ECG) before you start and while you are taking olanzapine.
  • Olanzapine can impair your ability to do tasks such as driving or using machines. Alcohol makes this worse. Discuss your risk with your health professional. (search NZTA - Are you safe to drive?)
  • Smoking can change the effect of olanzapine. Tell your doctor if you give up, cut down or start smoking.
  • Olanzapine reduces your body’s ability to maintain a normal temperature. Be careful of becoming too cold or too hot. When exercising, drink plenty of water.
  • You have an increased risk of getting diabetes while taking olanzapine. Discuss with your doctor.
  • Do not stop taking olanzapine without talking to your doctor first.

This leaflet contains important, but not all, information about this medicine.

Prepared by the PILs Committee at Christchurch Hospital, Canterbury District Health Board, New Zealand. January 2020

For more general information about this sheet and its contents, see: What does a My Medicines sheet cover?

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About My Medicines

My Medicines Patient Information Leaflets (PILs) contain important, but not all, information about the medicines they describe.

For more information about the sheets, see: What does a My Medicines sheet cover?

My Medicines is developed by a team at the Canterbury District Health Board. Our team is made up of doctors, pharmacists, and a non-medical person to help us keep to plain language. We also discuss our information with specialist health professionals or groups when needed