What are the Side Effects of the Atypical Antipsychotic Zyprexa?

Common and Rare Side Effects of Zyprexa

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Zyprexa, generic Olanzapine, is an atypical antipsychotic medication used in the treatment of bipolar disorder, schizophrenia, and treatment resistant depression.

Commonly Reported Side Effects of Zyprexa

Common side effects of Zyprexa include:

  • Sleepiness or excessive sleeping
  • Dizziness
  • Dry mouth
  • Lack of energy
  • Increased appetitie
  • Tremor
  • Hard or infrequent stools
  • Change in behavior
  • Restlessness

Be sure to consult your doctor if any of these side effects bother you or are persistent.

Also, there are some more unique side effects that teenagers may experience with Zyprexa -- be sure to review these with your doctor.

Potential Serious Side Effects with Zyprexa

One important and serious side effect of Zyprexa is significant weight gain, which is often a huge reason why a patient stops their medication. In addition, Zyprexa can also increase blood sugar levels, which can put a person at risk for developing diabetes. Zyprexa may also increase a person's cholesterol levels. All of these factors can increase a person's risk of heart disease. This is why it's important to review a exercise and nutritional plan with your doctor while on Zyprexa -- to help minimize these side effects.

A rare but very dangerous side effect of Zyprexa is neuroleptic malignant syndrome, or NMS. Signs of NMS include muscle rigidity, confusion, high fever, increased blood pressure and heart rate, and abnormal heart rhythms.

Tardive dyskinesia (TD) is another potentially irreversible, involuntary movement that may develop. Although the risk of tardive dyskinesia is lower when compared to typical or first generation antipsychotics.

In addition, it has been reported that people on Zyprexa may have an increased sensitivity to heat due to reduced sweating.

So be sure to drink plenty of water, especially in hot weather or before and after exercising.

Other potential serious side effects include seizures, dizziness or fainting when changing positions (like going from a sitting to standing position), problems swallowing, and an increased risk of transient ischemic attacks and strokes in elderly people with dementia-related psychosis.

What if My Doctor Prescribes Zyprexa?

It's important to first inform your doctor of all your medications -- this includes prescription, herbals, vitamins, or any over-the-counter medications. Some medications interact with Zyprexa, and may cause serious side effects or require that your doctor alter your dose. Also, never start or stop Zyprexa without seeking the advice of your doctor -- this is for your safety and well-being

It's also important to give your doctor a complete medical history, including all your medical problems and any allergies. For example, tell your doctor if you are lactose-intolerant, as Zyprexa tablets contain lactose.

Also, tell your doctor if you drink alcohol, as alcohol should not be used when taking Zyprexa.

Finally, when on Zyprexa, take it at the same time everyday. If you accidentally forget a dose, take it as soon as you remember -- unless, it's almost time for the next dose anyway. Then skip it, and take your regular dose as scheduled. Do not take two doses of Zyprexa at the same time. If you are unsure about your timing, call your doctor to be safe.


Eli Lily and Company. US Food and Drug Administration. (2009). Medication Guide: Zyprexa. Retrieved January 30th 2016. 

Nashed MG, Restivo MR & Taylor VH. Olanzapine-induced weight gain in patients with bipolar I disorder: A meta-analysis. Prim Care Companion CNS Disord. 2011;13(6):PCC

DISCLAIMER: The information in this site is for educational purposes only. It should not be used as a substitute for personal care by a licensed physician. Please see your doctor for diagnosis and treatment of any concerning symptoms or medical condition.

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