Olanzapine (Zyprexa)

Olanzapine, more commonly known by its brand name, Zyprexa®, is one of the second generation of neuroleptic drugs. It is also sold under the brand name Zyprexa Zidis®, which refers to the orally disintegrating pill form of the drug.

What it’s used to treat

Like the other atypical antipsychotics, olanzapine was initially approved to treat schizophrenia. It is also used to treat individuals with bipolar I disorder who are experiencing acute manic or mixed symptoms, as well as the ongoing treatment of bipolar disorder. When used for bipolar disorder, olanzapine is sometimes used in addition to other medications such as valproate or lithium.

Individuals who have severe depression and are experiencing psychotic symptoms are also sometimes treated effectively with olanzapine 1.

Olanzapine was approved by the FDA in 2009 for the treatment of teens, between the ages of 13 and 17, who have schizophrenia or bipolar disorder 2.

How it works

Although the exact processes are not fully understood, olanzapine effectively alleviates or reduces schizophrenic and manic symptoms by working on both serotonin and dopamine. These are brain chemicals known as neurotransmitters, which are believed to be out of balance in individuals with schizophrenia or bipolar disorder. It appears to block the receptors for serotonin more strongly than those for dopamine.

How it’s administered

Olanzapine can be taken orally as a regular tablet as well as a tablet which disintegrates orally (Zyprexa Zydis). It is also available as an injection.

Potential Side Effects

Just like the other antipsychotic medications, olanzapine can cause many side effects. One of the most troubling side effects experienced by many, but not all, individuals who take olanzapine is the tendency to gain a lot of weight. Some of the other more common side effects include:

  • Sedation
  • Fatigue
  • Increase in appetite
  • Light-headedness
  • Feelings of restlessness
  • Dry mouth
  • Shakiness
  • Constipation
  • Unusual changes in behavior
  • Difficulties sleeping

More serious side effects may include seizures, problems with vision, swelling in the extremities, drop in blood pressure, muscle stiffness, hives, problems with swallowing or breathing, rapid or irregular pulse and fever.

Although it is very rare, olanzapine may cause tardive dyskinesia (TD). TD symptoms involve involuntary, random and uncontrollable movements, such as lip smacking, odd tongue or jaw movements, blinking, grimacing, and movements involving the limbs, fingers, toes, upper body or hips. TD symptoms can be permanent for some patients, but has been known to be temporary for others.

Olanzapine may also potentially cause the development of a very serious condition known as neuroleptic malignant syndrome (NMS), although it is very rare with this particular drug. NMS is a potentially fatal condition. Some of the symptoms include muscle stiffness, changes in one’s mental state, fluctuations in blood pressure or heartbeat, sudden renal failure, tremors, difficulty breathing, dehydration, rapid heartbeat, and extremely high temperature.


As with all medications, there are many precautions which must be considered before starting treatment with olanzapine. You should tell your doctor if you (or a family member) have any history of heart or liver disease, seizures, phenylketonuria, kidney disease, high blood pressure, breast cancer, glaucoma, problems swallowing, prostrate or urination problems, elevated cholesterol, or a white blood cell count which has been low.

Also, if you are pregnant, thinking about becoming pregnant, or nursing, you need to let your doctor know. Olanzapine can increase the chances of death for elderly individuals who have dementia.

written by Dr. Cheryl Lane, PsyD


  1. "Olanzapine Response in Psychotic Depression, Journal of Clinical Psychiatry," Feb, 1999
  2. "FDA Approves Zyprexa for Bipolar Adolescents," Dec 2009