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Drug Class: Commonly Known As: Category:
Antipsychotics zyprexa Adult

olanzapine - What is it for

​Olanzapine belongs to a class of medicine known as the second generation antipsychotics.

It is used to treat symptoms of:

  • Psychosis (Including by not limited to symptoms of hallucinations, altered thought and emotions)
  • Bipolar disorder ( Alternating mood)


It may be given to you for other reasons. Do check with your doctor what you are taking this for.


olanzapine - Side Effects, Precautions, and Contraindications

What side effects can olanzapine cause?

Potential side effects

All medicines may cause side effects. However, many people do not experience them.

Most of the side effects listed here will improve with time. Speak with your doctor or pharmacist if they persist, become bothersome or worsen.


Side effectsWhat to do about it
Increased appetite and weight gainMaintain a healthy diet. Exercise regularly.

Increase your intake of fluids and include more fibre (vegetables and fruits) in your diet. Incorporate some exercise in your daily routine.

Consult your doctor or pharmacist if you require any laxatives.

Dry mouthSip water regularly. Sucking on sugar-free sweets or ice chips may help alleviate symptoms. Avoid caffeine as it may worsen dry mouth.
HeadacheConsult your doctor or pharmacist if you need any painkillers

Do not drive or operate any machinery.

Discuss with your doctor if you can take your medicine at a different time of the day. 

DizzinessGet up slowly from a lying or sitting position


Serious side effects

If you experience signs of allergy such as rashes, swelling of lips/face/throat and difficulty breathing, stop this medicine immediately and seek medical attention.

Olanzapine may cause unusual movements involving the face or tongue, muscle stiffness, shakiness and unsteadiness on your feet. Please notify your doctor if this happens while taking this medicine.

If you have symptoms such as changes in weight, passing of large amounts of urine and feelings of thirst and hunger all the time while taking this medicine, consult your doctor.

A condition known as Neuroleptic Malignant Syndrome may occur rarely. Symptoms include but are not limited to fever, muscle rigidity, altered mental state/ consciousness and/or irregular blood pressure, heart rhythm and palpitations. If you develop any of these symptoms or other unexplained symptoms while taking this medicine consult your doctor immediately, otherwise consult your doctor if you require further information regarding this condition.

Take note that the side effects listed here are not exhaustive. Do seek medical attention if you develop any unusual or other symptoms while taking this medicine.


Before taking olanzapine , what precautions must I follow?

​What do I need to tell my doctor before I take this medicine?

  • Drug allergies
  • Pre-existing medical conditions such as prior stroke, heart disease, diabetes, Parkinson's disease, seizures, blocked intestines, liver or kidney diseases, blood disorders, and prostate problems
  • Whether you are taking any other medicines, supplements or traditional medicines. Some of them may affect how this medicine works.
  • For women: Tell your doctor if you are pregnant or breast-feeding or have plans to become pregnant. If you are pregnant and/or breastfeeding, your doctor would have discussed the potential benefits and side-effects with continuing/starting this medication but should you have further questions or concerns, do consult your doctor.

What food or medicine must I avoid when I take olanzapine ?

​This medicine may interact with a number of other medicines. Inform your doctor if you are taking or intend to start taking other medicines or supplements.


olanzapine - Dosage and How to Use

How should olanzapine be used?

Take this medicine exactly as prescribed by your doctor. Follow the instructions on the medicine label or as advised by the pharmacist.

Olanzapine can be taken with or without food.

Orodispersible tablets

If you are taking the orodispersible tablet, the medicine dissolves once you place it inside your mouth.

How to remove orodispersible tablets from the blister pack:

  1. Make sure your hands are dry before handling the tablets as they dissolve when in contact with water.
  2. Cut out a square containing a tablet, along the dotted line.
  3. Peel off the backing of the blister pack, starting from the corner as indicated by an arrow.
  4. Consume the tablet as soon as possible. Do not remove the tablets too early from the blister pack.


This medicine may not have an effect immediately. It may take up to a few weeks before this medicine can exert its full effects. Continue taking it regularly to benefit from it.

Do not stop taking the medicine even after you feel better. Your symptoms may return if the medicine is stopped too early. Check with your doctor on the duration of treatment that is suitable for you.

Do not stop taking the medicine abruptly or change the dose without consulting your doctor. You may experience unpleasant side effects if this medicine is stopped suddenly.

Avoid taking alcohol while you are on this medicine.

What should I do if I miss a dose?

​Take the missed dose as soon as you remember. However, if it is close to the time for your next dose, skip the missed dose and take the next one at your usual timing.

Do not take 2 doses at the same time or extra doses.

What should I do if I overdose?

​If you take more than the dose prescribed to you by your doctor, consult your doctor or health care professional immediately.


olanzapine - Handling

How should I handle olanzapine safely?

olanzapine - Storage

How should I store olanzapine ?

;#Keep away from children;#Keep in a cool, dry place, away from direct sunlight;#Store at room temperature;#

How should I dispose of olanzapine safely?

​Throw away any unused or expired medicines. Consult your medical professional if you are unsure with respect to how to safely dispose of any excess medicines/expired medicines.


olanzapine - Additional Information

​What are the things I need to know or look out for while on this medicine?

  • Avoid driving or any other activities that requires concentration until you see how this drug affects you.
  • Be careful in hot weather or while being active. Drink lots of fluids to stop fluid loss.
  • Inform your other healthcare professionals that you are on this medicine as well.
  • Discuss with your doctor or pharmacist before you take any other medicines or natural products.
  • Do not share your medicines with others.
  • Consult your doctor or pharmacist if you have any questions about your medicine.

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