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Generic name: Olanzapine (oh LANZ a peen)
All FDA warnings are at the end of this fact sheet. Please consult them before taking this medication.
Olanzapine is a medication that works in the brain to treat schizophrenia. It is also known as a second-generation antipsychotic (SGA) or atypical antipsychotic. Olanzapine rebalances dopamine and serotonin to improve thinking, mood, and behavior.
Symptoms of schizophrenia include:
This medication sheet will focus primarily on schizophrenia. You can find more information about bipolar disorder and depression here.
This medication may be prescribed for other uses; ask your health care provider for more information.
Schizophrenia requires long-term treatment. Do not stop taking olanzapine, even when you feel better.
With input from you, your health care provider will assess how long you will need to take the medication.
Missing doses of olanzapine may increase your risk for a relapse in your symptoms.
Do not stop taking olanzapine or change your dose without talking with your health care provider first.
For olanzapine to work properly, it should be taken every day as ordered by your health care provider.
If you are planning on becoming pregnant, notify your health care provider to best manage your medications. People living with schizophrenia or certain other mental illness who wish to become pregnant face important decisions. This is a complex decision since untreated schizophrenia or other mental illness has risks to the fetus, as well as the mother. It is important to discuss the risks and benefits of treatment with your doctor and caregivers.
Antipsychotic use during the third trimester of pregnancy has a risk for abnormal muscle movements (extrapyramidal symptoms [EPS]) and/or withdrawal symptoms in newborns following delivery that may need to be monitored. These may resolve within hours/days without treatment or require hospitalization for monitoring/treatment.
Caution is advised with breastfeeding since olanzapine does pass into breast milk. It is recommended that women receiving olanzapine should not breastfeed.
Olanzapine may help control your symptoms but will not cure your condition.
It may take several weeks before you feel the full effect of olanzapine.
Olanzapine tablets are usually taken 1 time per day with or without food.
Typically, patients begin at a low dose of medication and the dose is increased slowly over several weeks.
The oral dose usually ranges from 5 mg to 20 mg. The dose of the long-acting injection usually ranges from 150 mg to 405 mg. Only your health care provider can determine the correct dose for you.
Olanzapine orally disintegrating tablets must remain in their original packaging. Open the package with clean dry hands before each dose. Do not try to put tablets in a pillbox if you take the orally disintegrating tablets.
Olanzapine orally disintegrating tablets will dissolve in your mouth within seconds and can be swallowed with or without liquid.
Use a calendar, pillbox, alarm clock, or cell phone alert to help you remember to take your medication. You may also ask a family member a friend to remind you or check in with you to be sure you are taking your medication.
The long-acting injection form of olanzapine is administered every 2 to 4 weeks. It should be administered by your health care professional through an injection into your buttocks area. A health care professional will keep you in a setting where you can be observed for at least 3 hours after each injection.
It is important to take your medication everyday as directed by your health care provider. Do not miss or skip a dose.
If you miss a dose of olanzapine, take it as soon as you remember, unless it is closer to the time of your next dose. Discuss this with your health care provider. Do not double your next dose or take more than what is prescribed. If you miss a dose of olanzapine long-acting injection, see your health care provider to receive your dose as soon as possible.
Avoid drinking alcohol or using illegal drugs while you are taking olanzapine. They may decrease the benefits (e.g., worsen your symptoms) and increase adverse effects (e.g., sedation) of the medication.
If an overdose occurs call your doctor or 911. You may need urgent medical care. You may also contact the poison control center at 1-800-222-1222.
A specific treatment to reverse the effects of olanzapine does not exist.
This is not a complete list. Talk with your health care provider for more information.
Common side effects
Low blood pressure, drowsiness, extrapyramidal symptoms, restlessness, dizziness, headache, fatigue, insomnia, increased prolactin, weight gain, increased appetite, cholesterol abnormalities, increased glucose, dry mouth, indigestion, constipation, liver function test abnormalities, weakness, accidental injury
Rare/serious side effects
Olanzapine may increase the blood levels of a hormone called prolactin. Side effects of increased prolactin levels include females losing their period, production of breast milk and males losing their sex drive or possibly experiencing erectile problems. Long term (months or years) of elevated prolactin can lead to osteoporosis, or increased risk of bone fractures.
Some people may develop muscle related side effects while taking olanzapine. The technical terms for these are “extrapyramidal symptoms” (EPS) and “tardive dyskinesia” (TD). Symptoms of EPS include restlessness, tremor, and stiffness. TD symptoms include slow or jerky movements that one cannot control, often starting in the mouth with tongue rolling or chewing movements.
Antipsychotics can also affect temperature regulation especially if you exercise a lot or are in an area that is very hot. While taking quetiapine, it is especially important to try to drink water to avoid dehydration. Second generation antipsychotics (SGAs) increase the risk of weight gain, high blood sugar, and high cholesterol. This is also known as metabolic syndrome. Your health care provider may ask you for a blood sample to check your cholesterol, blood sugar, and hemoglobin A1c (a measure of blood sugar over time) while you take this medication.
All antipsychotics have been associated with the risk of sudden cardiac death due to an arrhythmia (irregular heart beat). To minimize this risk, antipsychotic medications should be used in the smallest effective dose when the benefits outweigh the risks. Your doctor may order an EKG to monitor for irregular heartbeat.
Neuroleptic malignant syndrome is a rare, life-threatening adverse effect of antipsychotics which occurs in <1% of patients. Symptoms include confusion, fever, extreme muscle stiffness, and sweating. If any of these symptoms occur, contact your health care provider immediately.
All antipsychotics can cause sedation, dizziness, or orthostatic hypotension (a drop in blood pressure when standing up from sitting or lying down). These side effects may lead to falls which could cause bone fractures or other injuries. This risk is higher for people with conditions or other medications that could worsen these effects. If falls or any of these symptoms occur, contact your health care provider.
Multiorgan hypersensitivity reactions (drug reaction with eosinophilia and systemic symptoms [DRESS]): Potentially serious, sometimes fatal, multiorgan hypersensitivity reactions have been reported. Symptoms may include a rash, increased levels of certain white blood cells (eosinophils), fever, and/or swollen/enlarged lymph nodes with systemic complications. If DRESS is suspected, contact your health care provider immediately.
Tardive dyskinesia (TD) is a side effect that develops with prolonged use of antipsychotics. Medications such as olanzapine have been shown to have a lower risk of TD compared to older antipsychotics, such as Haldol (haloperidol).] If you develop symptoms of TD, such as grimacing, sucking, and smacking of lips, or other movements that you cannot control, contact your health care provider immediately. All patients taking either first- or second-generation antipsychotics should have an Abnormal Involuntary Movement Scale (AIMS) completed regularly by their health care provider to monitor for TD.
Second generation antipsychotics (SGAs) increase the risk of diabetes, weight gain, high cholesterol, and high triglycerides. (See “Serious Side Effects” section for monitoring recommendations).
Tell your health care provider about all medications that you take, have recently taken or plan to take including prescription and nonprescription medications, vitamins, herbal products, and nutritional supplements. This medication may affect the way other medications work, and other medications may affect how this medication works.
Olanzapine may block the effects of agents used to treat Parkinson’s disease such as levodopa/carbidopa (Sinemet®), bromocriptine, pramipexole (Mirapex®), ropinirole (Requip®), and others.
Olanzapine may lower your blood pressure. Medications used to lower blood pressure may increase this effect and increase your risk of falling. Propranolol (Inderal®) is an example of this type of medication.
Sedative medications, such as lorazepam (Ativan®) and diazepam (Valium®) may increase the risk of dizziness or sleepiness when used in combination with olanzapine. This risk is increased when these medications are given as an injection.
The following medications may increase the levels and effects of olanzapine: ciprofloxacin (Cipro®) and fluvoxamine (Luvox®)
Carbamazepine (Tegretol®) may decrease the levels and effects of olanzapine.
Cigarette (and other types of) smoke can decrease levels of olanzapine. Let your health care provider know if you start or stop smoking cigarettes. Nicotine replacement therapies, such as patches and gum, do not impact olanzapine levels.
It is very important to tell your doctor how you feel things are going during the first few weeks after you start taking olanzapine. It will probably take several weeks to see big enough changes in your symptoms to decide if olanzapine is the right medication for you.
Antipsychotic treatment is generally needed lifelong for persons with schizophrenia. Your doctor can best discuss the duration of treatment you need based on your symptoms and illness.
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Last Reviewed: January 2024
Important Disclosure: This information is being provided as a community outreach effort of the American Association of Psychiatric Pharmacists. This information is for educational and informational purposes only and is not medical advice. This information contains a summary of important points and is not an exhaustive review of information about the medication. Always seek the advice of a physician or other qualified medical professional with any questions you may have regarding medications or medical conditions. Never delay seeking professional medical advice or disregard medical professional advice as a result of any information provided herein. The American Association of Psychiatric Pharmacists disclaims any and all liability alleged as a result of the information provided herein.
©2023 The American Association of Psychiatric Pharmacists (AAPP) and the National Alliance on Mental Illness (NAMI). AAPP and NAMI make this document available under the Creative Commons Attribution-NoDerivatives 4.0 International License. Last Updated: January 2016.