Zyprexa (Olanzapine) Side Effects

Common and Rare Side Effects of Zyprexa

Mental health professional prescribing medication

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Zyprexa (olanzapine) is an atypical antipsychotic medication used in the treatment of bipolar disorder, schizophrenia, and treatment-resistant depression. It can be used for new onset of disease and long-term maintenance of schizophrenia. For bipolar disorder, it is considered a first-line therapy for acute mania. Side effects with Zyprexa are possible (as with most medicines), but its benefits may outweigh the side effects for you.

Commonly Reported Zyprexa Side Effects

Common side effects of Zyprexa include:

  • Dizziness
  • Dry mouth
  • Hard or infrequent stools
  • Increased appetite
  • Lack of energy
  • Sleepiness or excessive sleeping
  • Tremor
  • Weight gain

Be sure to consult your doctor if any of these side effects bother you or persist. It's important to note that there are also some unique side effects that teenagers may experience with Zyprexa, so be sure to review these with your doctor. Adolescents may be more likely to experience weight gain and hyperlipidemia (a condition where there are high levels of lipids in the blood).

Potential Serious Side Effects With Zyprexa

One common and possibly serious side effect of Zyprexa is significant weight gain, which has been reported as one of the top reasons people choose to stop taking the medication. It's important to note that weight gain is also dose-dependent—the higher your dosage, the more weight you are likely to gain. In addition, Zyprexa can increase blood sugar levels, putting a person at risk for developing diabetes. Zyprexa may also increase an individual's cholesterol levels.

All three of these factors combined—weight gain, high blood sugar, and high cholesterol—can increase the patient's risk of heart disease, which is why it's important to review an exercise and nutritional plan with your doctor while on Zyprexa.

Other serious side effects of Zyprexa can include:

  • Neuroleptic malignant syndrome (NMS): Signs include muscle rigidity, confusion, high fever, alterations in blood pressure and heart rate, and abnormal heart rhythms.
  • Tardive dyskinesia: Condition that can occur with the long term use of antipsychotics that causes repetitive, involuntary movements, though the risk of tardive dyskinesia on Zyprexa is lower when compared to typical or first-generation antipsychotics.
  • Heat sensitivity: You also may be more sensitive to heat. So be sure to drink plenty of water, especially in hot weather or before and after exercising.
  • Seizures: Zyprexa can lower the seizure threshold, though this is a rare occurrence.
  • Dysphagia: Problems swallowing may occur.
  • Stroke: An increased risk of strokes in older adults with dementia-related psychosis also exists.
  • Orthostatic hypotension: This is dizziness or fainting when going from sitting to standing due to low blood pressure.

Black Box Warning

Zyprexa is not approved for older adults with dementia-related psychosis, as the drug can increase the risk of death in this population by 60% to 70%. The FDA placed a black box warning on all antipsychotics (atypical and typical) due to this increased mortality risk.

What If My Doctor Prescribes Zyprexa?

You'll want to share with your doctor of all the medications you take including prescription medication, herbals, vitamins, and any over-the-counter medications. Some medications interact with Zyprexa and may cause serious side effects or require that your doctor change your dose. Never start or stop Zyprexa without seeking the advice of your doctor.

It's also important to give your doctor a complete medical history, including all your medical problems and allergies. For example, tell your doctor:

  • If you are lactose-intolerant, as Zyprexa tablets contain lactose
  • If you drink alcohol, as alcohol should be used cautiously if at all when taking Zyprexa
  • If you are breastfeeding, as there may be potential risks that you should discuss with your doctor

Finally, when on Zyprexa, try and take it at the same time every day. 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.

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7 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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