Olanzapine belongs to group of medications known as antipsychotic agents. Olanzapine is used to treat schizophrenia and related mental disorders, as well as bipolar disorder.

Schizophrenia can cause symptoms such as hallucinations (e.g., hearing, seeing, or sensing things that are not there), delusions, unusual suspiciousness, and emotional withdrawal. People with this condition may also feel depressed, anxious, or tense.

Bipolar disorder can cause alternating periods of depression and mania (abnormally elevated or irritable mood) or "mixed episodes" where people have symptoms of both depression and mania. Olanzapine may be used, alone or in combination with other medications, to treat the manic or mixed episodes (but not the depression) of bipolar disorder.

Medications like olanzapine are thought to work by correcting the balance of neurotransmitters (chemicals that control the function of nerve pathways) in the brain.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The usual starting dose of olanzapine tablets for adults with schizophrenia is 5 mg to 10 mg once daily at the same time each day, taken with or without food. The tablets should be swallowed whole with a full glass of water. If the daily dose is increased, it is usually raised not more than once a week, and in increments of 5 mg. The dosage range is 5 mg to 20 mg daily.

The usual starting dose of olanzapine tablets for adults with bipolar disorder is 10 mg daily (if olanzapine is used in combination with other medications that treat bipolar disorder) or 15 mg daily (if olanzapine is used alone). The dose may be increased up to 20 mg daily. For the maintenance treatment of bipolar disorder, the dose ranges from 5 mg to 20 mg daily. The tablets should be swallowed whole with a full glass of water and can be taken with or without food.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are using the medication without consulting your doctor.

For this medication to be effective, it is very important to use this medication exactly as prescribed by your doctor.

If you miss a dose, take it as soon as possible and continue with your regular dosing schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take two doses at the same time. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store the medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

2.5 mg
Each white-to-off-white, round, biconvex, film-coated tablet, debossed with "27" on one side and "I" on other side, contains the equivalent activity of 2.5 mg (8 μmol) of olanzapine. Nonmedicinal ingredients: crospovidone, hydroxypropylcellulose, lactose monohydrate, macrogol polyvinyl alcohol grafted copolymer, magnesium stearate, purified water, talc, and titanium dioxide.

5 mg
Each white-to-off-white, round, biconvex, film-coated tablet, debossed with "19" on one side and "I" on other side, contains the equivalent activity of 5 mg (16 μmol) of olanzapine. Nonmedicinal ingredients: crospovidone, hydroxypropylcellulose, lactose monohydrate, macrogol polyvinyl alcohol grafted copolymer, magnesium stearate, purified water, talc, and titanium dioxide.

7.5 mg
Each white-to-off-white, round, biconvex, film-coated tablet, debossed with "28" on one side and "I" on other side, contains the equivalent activity of 7.5 mg (24 μmol) of olanzapine. Nonmedicinal ingredients: crospovidone, hydroxypropylcellulose, lactose monohydrate, macrogol polyvinyl alcohol grafted copolymer, magnesium stearate, purified water, talc, and titanium dioxide.

10 mg
Each white-to-off-white, round, biconvex, film-coated tablet, debossed with "29" on one side and "I" on other side, contains the equivalent activity of 10 mg (32 μmol) of olanzapine. Nonmedicinal ingredients: crospovidone, hydroxypropylcellulose, lactose monohydrate, macrogol polyvinyl alcohol grafted copolymer, magnesium stearate, purified water, talc, and titanium dioxide.

15 mg
Each light blue, oval, biconvex, film-coated tablet, debossed with "30" on one side and "I" on other side, contains the equivalent activity of 15 mg (48 μmol) of olanzapine. Nonmedicinal ingredients: crospovidone, FD&C Blue No. 2/Indigo Carmine Aluminum Lake, hydroxypropylcellulose, lactose monohydrate, macrogol polyvinyl alcohol grafted copolymer, magnesium stearate, purified water, talc, and titanium dioxide.

20 mg
Each light pink, oval, biconvex, film-coated tablet, debossed with "31" on one side and "I" on other side, contains the equivalent activity of 20 mg (64 μmol) of olanzapine. Nonmedicinal ingredients: crospovidone, ferric oxide, hydroxypropylcellulose, lactose monohydrate, macrogol polyvinyl alcohol grafted copolymer, magnesium stearate, purified water, talc, and titanium dioxide.

Do not take this medication if you are allergic to olanzapine or any ingredients of the medication.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• constipation
• dizziness, especially when rising quickly from a lying or sitting position
• drowsiness
• dry mouth or eyes
• fatigue
• fluid retention
• increased appetite
• increased saliva production
• rash
• restlessness
• weakness
• weight gain

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• changes in your menstrual period (for women)
• enlarged breasts (in men)
• signs of a blood clot in the arm or leg (tenderness, pain, swelling, warmth, or redness in the arm or leg) or lungs (difficulty breathing, sharp chest pain that is worse when breathing in, coughing, coughing up blood, sweating, or passing out)
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don’t stop bleeding)
• signs of liver damage (abdominal pain, abdominal distention, fever, nausea or vomiting, yellowing of the skin or eyes)
• signs of muscle damage (e.g., unexplained muscle pain, tenderness or weakness, or brown or discoloured urine)
• signs of pancreatitis (e.g., abdominal pain on the upper left side, back pain, nausea, fever, chills, rapid heartbeat, swollen abdomen)
• slow, irregular, or fast heartbeat
• stuttering
• symptoms of high blood sugar (e.g., frequent urination, increased thirst, excessive eating, unexplained weight loss, poor wound healing, infections, fruity breath odour)
• symptoms of infection (cold or flu-like symptoms, fever, sore throat, as well as weakness or general feeling of discomfort)
• twitching of your muscles or unusual facial or tongue movements
• worsening constipation

Stop taking the medication and seek immediate medical attention if any of the following occur:

• painful erection or prolonged erection that lasts more than 4 hours
• seizure
• signs of an allergic reaction (shortness of breath or difficulty breathing; hives; swelling of the eyes, mouth, lips, or throat)
• signs of neuroleptic malignant syndrome (e.g., confusion, reduced consciousness, high fever, or muscle stiffness)
• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort
• signs of stroke (e.g., sudden or severe headache; sudden loss of coordination; vision changes; sudden slurring of speech; or unexplained weakness, numbness, or pain in arm or leg)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Blood clots: This medication may increase the chance of blood clot formation, causing reduction of blood flow to organs or the extremities.

If you have a history of clotting you may be at increased risk of experiencing blood clot-related problems such as heart attack, stroke, or clots in the deep veins of your leg. Discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you experience symptoms such as sharp pain and swelling in the leg, difficulty breathing, chest pain, blurred vision, or difficulty speaking, contact your doctor immediately.

Body temperature: This medication, like other antipsychotic medications, can disrupt the body's ability to control body temperature. If you exercise vigorously, are exposed to extreme heat, are dehydrated, or are taking anticholinergic medications (e.g., benztropine, oxybutynin) you are more at risk. Contact your doctor as soon as possible if you feel very hot and are unable to cool down while taking this medication.

Cholesterol: Olanzapine can cause increased blood cholesterol levels. If you are at risk of developing high cholesterol or you have high cholesterol levels before starting olanzapine, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Drowsiness/reduced alertness: Olanzapine may impair the mental and physical abilities required for driving a car or operating machinery. Avoid drinking alcohol while taking this medication, as it may produce extreme drowsiness.

Glaucoma: This medication may cause the symptoms of glaucoma (increased pressure in the eye) to develop or become worse. If you have glaucoma, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Report any changes in vision to your doctor as soon as possible while you are taking this medication.

High blood sugar: Olanzapine, in rare instances, may cause an increase in blood sugar levels. Your doctor will monitor you if you have diabetes or are at risk of developing diabetes. If you experience weakness, increased thirst, increased urination, and increased appetite while taking this medication, contact your doctor.

Hypersensitivity reactions: A severe allergic reaction called hypersensitivity syndrome has occurred for some people with the use of olanzapine. This reaction involves a number of organs in the body and may be fatal if not treated quickly. Stop taking the medication and get immediate medical attention if you have symptoms of a severe allergic reaction, including fever, swollen glands, yellowing of the skin or eyes, or flu-like symptoms with skin rash or blistering.

Liver disease: Olanzapine can affect liver function and cause liver problems. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking this medication.

If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Low blood pressure: Olanzapine may cause low blood pressure, especially when moving from a lying or sitting position to a standing position. If you have heart disease, cerebrovascular disease, or conditions that increase the risk of developing low blood pressure (e.g., dehydration, treatment with blood pressure medications) you should be monitored by your doctor.

Neuroleptic malignant syndrome (NMS): Olanzapine, like other antipsychotic medications, can cause a potentially fatal syndrome known as neuroleptic malignant syndrome (NMS). If you notice the symptoms of NMS such as high fever, confusion or loss of consciousness, racing or irregular heartbeat, muscle stiffness, or sweating, get immediate medical attention.

Phenylketonuria: People with phenylketonuria (an inherited disorder where the enzyme needed to break down phenylalanine is lacking) should take the regular tablet forms of olanzapine and not the oral dissolving tablets (ODT). Some brands of the ODT form of olanzapine contain aspartame, which is a source of phenylalanine.

Prolonged erection: In rare cases, use of this medication by some men may cause them to develop priapism (a prolonged and painful erection). If you have an erection that lasts for more than 4 hours, contact your doctor.

Seizures: Olanzapine may increase the risk of seizures, especially if you have had seizures in the past. If you are at risk of seizures and take this medication, you should be closely monitored by your doctor.

Suicidal or self-harm behaviour: People taking this medication may want to hurt themselves or others. These symptoms may occur within several weeks after starting this medication. If you experience these side effects or notice them in a family member who is taking this medication, contact your doctor immediately. You should be closely monitored by your doctor for emotional and behaviour changes while taking this medication.

Tardive dyskinesia (TD): TD, a syndrome consisting of potentially irreversible, involuntary, repetitive movements of the face and tongue muscles, may develop in people who take certain antipsychotic medications including olanzapine.

Although TD appears most commonly in seniors, especially women, it is impossible to predict who will develop TD. The risk of developing TD increases with higher doses and long-term treatment. If your experience muscle twitching or abnormal movements of the face or tongue, contact your doctor as soon as possible.

Urinary problems: This medication can cause urinary retention. If you have a history of urinary retention or benign prostatic hypertrophy, or other prostate problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Weight gain: With long-term treatment, weight gain (averaging 5.4 kg) has occurred in people who take this medication. Weight gain tends to level off after 6 to 8 months of treatment.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Babies born to parents that took this medication in the last 3 months of pregnancy may experience withdrawal symptoms after they are born, including breathing problems, difficulty feeding, or irritability. If you have been taking this medication during pregnancy, make sure that everyone involved in caring for you and your baby are aware.

Breast-feeding: This medication passes into breast milk. People taking this medication should not breast-feed.

Children: The safety and effectiveness of using this medication have not been established for children under the age of 18.

Seniors: There may be a higher risk of strokes, heart attacks, and deaths associated with the use of olanzapine by seniors with dementia. Seek medical attention immediately if you notice the signs and symptoms of a stroke (e.g., sudden weakness or numbness, speech problems, vision problems, dizziness, confusion, sudden severe headache) or a heart attack (e.g., discomfort or pain in the chest, back, neck, jaw, arms; sweating; shortness of breath; nausea; lightheadedness) or infection (e.g., pneumonia). Olanzapine should not be used in seniors with dementia.

For a full list of interactions, use the Drug Interaction Checker available on the Drugs.com website.

If you are taking other medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.