Zyprexa (Olanzapine) Side Effects

Common, Less Common and Serious Side Effects


Pillbox / Zyprexa

Zyprexa (olanzapine) is used to treat schizophrenia and acute manic episodes in bipolar disorder. It is classed as an atypical antipsychotic.

How Zyprexa Works

Zyprexa works by balancing out the neurotransmitters dopamine and serotonin. This helps to improve mood, behavior and thinking.

Common Side Effects of Zyprexa

Check with your doctor if any of the following common side effects continue or are bothersome:

  • Constipation
  • Dizziness
  • Dizziness or fainting when getting up suddenly from a lying or sitting position
  • Drowsiness
  • Dry mouth
  • Headache
  • Runny nose
  • Vision problems
  • Weakness
  • Weight gain

Less Common Side Effects of Zyprexa

Check with your doctor if any of the following less common side effects continue or are bothersome:

  • Abdominal pain
  • Awareness of heartbeat
  • Decrease in sexual desire
  • Double vision
  • Fast heartbeat
  • Increased appetite
  • Increased cough
  • Increased sensitivity of skin to sunlight
  • Joint pain
  • Low blood pressure
  • Nausea
  • Sore throat
  • Stuttering
  • Thirst
  • Tightness of muscles
  • Trouble controlling urine
  • Trouble sleeping
  • Vomiting
  • Mouth watering
  • Weight loss

Serious Side Effects of Zyprexa

If you experience any of these serious side effects, always notify your doctor.

More common:

  • Agitation
  • Behavior problems
  • Difficulty in speaking or swallowing
  • Restlessness or need to keep moving
  • Stiffness of the arms or legs
  • Trembling or shaking of the hands and fingers

Less common:

  • Chest pain
  • Fever
  • Flu-like symptoms
  • Inability to move your eyes
  • Lip smacking or puckering
  • Mood or mental changes, such as anger, anxiety, giddiness, loss of memory, or nervousness
  • Muscle spasms of face, neck, and back
  • Puffing of cheeks
  • Rapid or worm-like movements of the tongue
  • Swelling of the feet or ankles
  • Twitching movements
  • Uncontrolled chewing movements
  • Uncontrolled movements of the arms and legs


  • Changes in menstrual period
  • Confusion
  • Mental or physical sluggishness
  • Skin rash
  • Swelling of the face
  • Trouble in breathing

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

Other Precautions Regarding Zyprexa

There are some other precautions you should be aware of if you're taking or plan to take Zyprexa. Be sure to talk to your doctor about any of the following that apply: 

  • A family history of heart disease or diabetes
  • If you're pregnant, plan to become pregnant, or are breastfeeding
  • Medications that you have previously used for your disorder and how they affected you, including side effects
  • Other illnesses or medical problems that you have
  • All the other medications you are taking, including over-the-counter medications like ibuprofen or acetaminophen, vitamins and supplements
  • Whether you have ever had symptoms of tardive dyskinesia, weight gain, muscle stiffness or shaking as a result of your medications

Symptoms of a Manic Episode

Zyprexa is used to help balance out mood episodes in bipolar disorder, particularly manic episodes. Symptoms of mania include:

  • Not needing as much sleep
  • Feeling distracted
  • Racing thoughts
  • Talking a lot more than usual
  • Feeling extremely self-confident and self-important
  • Feeling agitated and/or engaging in extremely goal-oriented behavior
  • Engaging in risky behaviors, such as gambling, shopping sprees or unprotected sex with strangers

To be classified as a manic episode, three or more of the above symptoms need to be present and they have to either be severe enough to significantly impair your work, school and/or social activities and relationships with others; require hospitalization; or cause psychosis.

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Article Sources

  • "Bipolar Disorder: Symptoms." Mayo Clinic (2015).
  • "Olanzapine." MedLine Plus, U.S. National Library of Medicine (2015).
  • "Olanzapine (Zyprexa)." National Alliance on Mental Illness (2013).