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Overview: Olanzapine/fluoxetine is used for certain types of depression. It works by changing the levels of certain chemicals in your brain. Some common side effects include drowsiness, tiredness, increased appetite, weight gain, and dry mouth. Contact your healthcare provider right away if you have dizziness, confusion, muscle stiffness, or you develop a fever.

Uses

What is olanzapine/fluoxetine used for?

Olanzapine/fluoxetine is commonly used to treat the following conditions.

Olanzapine/fluoxetine may also be used for other conditions as determined by your healthcare provider.

How does olanzapine/fluoxetine work (mechanism of action)?

Olanzapine/fluoxetine is a combination medicine that contains two active ingredients, olanzapine and fluoxetine. 

Olanzapine belongs to a group of medicines called second-generation (atypical) antipsychotics. It is thought to work by balancing brain chemicals called serotonin and dopamine. These chemicals are known to affect thoughts and mood. 

Fluoxetine is an antidepressant that belongs to a group of medicines called selective serotonin reuptake inhibitors (SSRIs). It works by increasing the amount of a natural chemical called serotonin in the brain.

How is olanzapine/fluoxetine supplied (dosage forms)?

Brands and other names

  • Symbyax

Dosage forms and strengths

  • 3 mg/25 mg oral capsules
  • 6 mg/25 mg oral capsules
  • 6 mg/50 mg oral capsules
  • 12 mg/25 mg oral capsules
  • 12 mg/50 mg oral capsules

How should I store olanzapine/fluoxetine?

Olanzapine/fluoxetine should be stored in a tightly closed container at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place. Protect it from moisture and light.

Side Effects

What are the most common side effects of olanzapine/fluoxetine?

The most common side effects of olanzapine/fluoxetine are listed below. These side effects may vary based on age. Tell your healthcare provider if you have any of these side effects that bother you.

  • Drowsiness or tiredness
  • Metabolism problems (such as increased weight, increased triglyceride levels) (see below)
  • Increased appetite
  • Dry mouth
  • Fluid retention (edema)
  • Tremor or shakiness
  • Blurred vision
  • Difficulty paying attention
  • Increased liver enzymes (children and adolescents)

There may be other side effects of olanzapine/fluoxetine that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of olanzapine/fluoxetine?

While less common, the most serious side effects of olanzapine/fluoxetine are described below, along with what to do if they happen.

Suicidal Thoughts or Actions. Olanzapine/fluoxetine or other antidepressants may increase the risk of suicidal thoughts or actions in a small number of children, teenagers, or young adults. The risk is higher in the first few months of taking the medicine or when the dose is changed. Depression or other serious mental health conditions are the most important causes of suicidal thoughts or actions. If you or your child is about to harm themselves, call 911 or call or text 988, the Suicide & Crisis Lifeline. Call your healthcare provider right away if you have any of the following symptoms.

  • New or increased thoughts of suicide or death
  • Suicide attempt
  • New or increased feelings of anxiety, depression, or other unusual changes in your mood or behavior

Neuroleptic Malignant Syndrome (NMS). Antipsychotic medicines, like olanzapine/fluoxetine, can cause a rare but serious condition called neuroleptic malignant syndrome. NMS is a serious condition that can lead to death. Stop taking olanzapine/fluoxetine and call your healthcare provider right away if you have any of the following symptoms.

  • High fever
  • Muscle stiffness or rigidity, where it is hard to move
  • Changes in your breathing, heart rate, or blood pressure
  • Increased sweating
  • Confusion

Metabolism Problems. Olanzapine/fluoxetine can cause high blood sugar levels or diabetes, high cholesterol levels, and weight gain. Keep all appointments with your healthcare provider to check your blood work and weight. Call your healthcare provider if you gain weight or develop the following symptoms of high blood sugar.

  • Thirsty more than usual
  • Peeing more than usual
  • Increase in hunger
  • Tiredness
  • Feeling sick to your stomach
  • Confusion
  • Your breath smelling fruity

Serotonin Syndrome. Serotonin syndrome is when there is too much of a substance called serotonin in your body. Olanzapine/fluoxetine can cause serotonin syndrome when it is taken alone or with other medicines that affect serotonin. This condition can be life-threatening. Get emergency help if you have any of the following symptoms of serotonin syndrome.

  • Feeling agitated
  • Seeing or hearing things that others do not see or hear, also called hallucinations
  • Blood pressure changes or a fast heartbeat
  • Poor coordination
  • Sweating, fever, or flushing
  • Confusion
  • Feeling agitated or restless
  • Seeing or hearing unusual things
  • Dizziness
  • Fast or racing heartbeat
  • Nausea, vomiting, or diarrhea
  • Muscle twitching, stiffness, or tremor
  • Seizures

Severe Allergic Reactions. Olanzapine/fluoxetine may cause allergic reactions, including a specific type of allergic reaction called DRESS. DRESS stands for Drug Reaction with Eosinophilia and Systemic Symptoms. It is also sometimes called multi-organ hypersensitivity. This is a reaction that can affect multiple parts of the body including your liver, kidneys, and heart. Stop taking the medicine and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Shortness of breath, trouble swallowing, or throat tightness
  • Swelling in your feet, ankles, or legs
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain
  • Dark-colored pee
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Extremely Elevated Mood (Mania). People with bipolar disorder can have severe high and low moods. The first symptom of bipolar disorder may be depression. People with bipolar disorder who take an antidepressant, such as olanzapine/fluoxetine, may have a higher risk of having mania or a manic episode. Call your healthcare provider right away if you have any of the following symptoms of a manic episode.

  • Very increased energy
  • Significant trouble sleeping
  • Racing, fast-paced thoughts
  • Reckless behavior
  • Unusually grand ideas
  • Excessive happiness or irritability
  • Talking more or faster than usual

Uncontrolled Movements. Olanzapine/fluoxetine can cause some people to have movements that they cannot control. This condition, called tardive dyskinesia (TD), can cause jerky movements of your face, tongue, or body. TD can be permanent. Call your healthcare provider right away if you have any symptoms of TD.

  • Tongue sticking out
  • Lip smacking or puckering
  • Grimacing
  • Rapid eye blinking
  • Jerking or twisting motion of the arms, legs, or trunk

Low Blood Pressure Upon Standing (Orthostatic Hypotension) and Falls. Olanzapine/fluoxetine may cause a sudden drop in blood pressure when standing up from a seated or lying position. This may sometimes lead to falls. Falls can cause serious problems or injuries like breaking a bone. To help prevent this, be careful not to get up too quickly. If you feel dizzy, sit or lie down right away until the dizziness stops, then take your time getting up again. Tell your healthcare provider right away if you fall or have any of the following symptoms of orthostatic hypotension.

  • Dizziness, feeling lightheaded, or fainting upon standing
  • Blurred vision
  • Confusion
  • Feeling weak

Blood Disorders. Olanzapine/fluoxetine can cause blood disorders, such as agranulocytosis, low platelet levels (thrombocytopenia), and low white blood cell levels (leukopenia or neutropenia). Stop taking olanzapine/fluoxetine and get help right away if you have any of the following symptoms of blood disorders.

  • Fever
  • Shortness of breath
  • Pale or yellowish skin
  • Easy bruising or bleeding
  • Frequent infection
  • Unusual weakness or tiredness
  • Dizziness, lightheadedness, or feeling like you are about to pass out
  • Headache
  • Fast or abnormal heartbeat

Trouble Swallowing. Olanzapine/fluoxetine can cause trouble swallowing (dysphagia), which can increase your risk of choking while eating or drinking. Eat small amounts of food, and chew your food well. Get emergency help if you are choking or have food stuck in your esophagus that is not passing.

Seizures. Some people who have taken olanzapine/fluoxetine have reported having seizures. There are many different types of seizures and some of them are not easy to recognize. Stop taking olanzapine/fluoxetine and call your healthcare provider if you have any of the following signs that a seizure is happening or could happen.

  • Muscle twitching, jerking, spasms, tremors, or other uncontrolled movements
  • Stiffening of your arms and legs
  • Feeling anxious, nervous, confused, or a sense of dread
  • Feeling dizzy or lightheaded
  • Falling or losing consciousness

Abnormal Bleeding. People taking olanzapine/fluoxetine or other antidepressants may have an increased risk of bleeding or bruising. You may be at higher risk if you are also taking aspirin, a nonsteroidal anti-inflammatory drug (NSAID), like ibuprofen or naproxen, or a blood thinner such as warfarin. Tell your healthcare provider if you notice any changes in how easily you bruise or bleed.

Low Sodium Levels (Hyponatremia). Olanzapine/fluoxetine may cause low sodium levels. Call your healthcare provider if you have any of the following symptoms of a low sodium level.

  • Headache
  • Drowsiness
  • Muscle weakness or cramps
  • Nausea, vomiting, or loss of appetite
  • Tiredness or sleepiness
  • Dizziness
  • Weight gain
  • Restlessness or irritability
  • Change in your mental condition such as hallucinations, confusion, decreased awareness, memory problems, or alertness
  • Seizures
  • Feeling unsteady

Decreased Alertness or Coordination. Olanzapine/fluoxetine can affect your alertness or coordination. Do not drive or do other activities that require alertness or coordination until you know how olanzapine/fluoxetine affects you.

Body Temperature Regulation. Olanzapine/fluoxetine can affect your ability to regulate your body temperature. This could make you become very hot, especially in hot weather or after exercising a lot. You should drink water and avoid overheating and dehydration. Call your healthcare provider right away if you are severely ill and have the following symptoms.

  • Excessive or no sweating
  • Dry mouth
  • Feeling very hot
  • Feeling thirsty 
  • Not able to pee

Heart Rhythm Changes. Olanzapine/fluoxetine may cause a rare, dangerous heart rhythm problem called QT prolongation and torsade de pointes. Some people have a higher risk of this, including people who are older, have other people in their family who have had these conditions, have low potassium or magnesium levels, or who take medicines that can prolong the QT interval. Tell your healthcare provider right away if you feel dizzy like you might faint, short of breath, or have changes in your heart rate or rhythm, such as a slow, fast, or skipping heartbeat.

High Prolactin Levels (Hyperprolactinemia). Olanzapine/fluoxetine may cause an increased level of the hormone prolactin in your blood. Increased levels of prolactin could lead to fertility or bone problems. Contact your healthcare provider if you have any of the following symptoms.

  • Vaginal dryness
  • Irregular or no periods 
  • Production of breastmilk when not pregnant or nursing
  • Inability to get or keep an erection
  • Enlarged breast size (gynecomastia)
  • Decreased muscle and body hair

Sexual Problems. Taking olanzapine/fluoxetine or another selective serotonin reuptake inhibitor (SSRI) may cause sexual problems. Tell your healthcare provider if you have any of the following sexual problems. 

  • Decreased sex drive
  • Delayed ejaculation or unable to have an ejaculation
  • Problems getting or keeping an erection
  • Delayed orgasm or unable to have an orgasm

Warnings & Precautions

Who should not use olanzapine/fluoxetine?

Allergies to Ingredients. People who are allergic to any of the following should not take olanzapine/fluoxetine.

  • Olanzapine
  • Fluoxetine
  • Symbyax
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific olanzapine/fluoxetine products they stock.

Drug Interactions. Olanzapine/fluoxetine should not be taken while you are using certain other medicines. Before taking olanzapine/fluoxetine, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

What should I know about olanzapine/fluoxetine before using it?

Do not take olanzapine/fluoxetine unless it has been prescribed to you by a healthcare provider. Take it as prescribed, usually in the evening.

Do not share olanzapine/fluoxetine with other people, even if they have the same condition as you. It may harm them.

Keep olanzapine/fluoxetine out of the reach of children.

Olanzapine/fluoxetine can affect your alertness or coordination. Do not drive or do other activities that require alertness or coordination until you know how olanzapine/fluoxetine affects you.

Do not stop taking olanzapine/fluoxetine without talking to your healthcare provider. Stopping too quickly may cause serious side effects. Call your healthcare provider right away if you have any of the following symptoms.

  • Irritability or feeling agitated
  • High or low energy or low mood
  • Anxiety
  • Feeling restless 
  • Trouble sleeping
  • Headache
  • Dizziness
  • Electric-shock like feelings
  • Confusion

Older adults and children, adolescents, or young adults can be at greater risk for some side effects from olanzapine/fluoxetine. Talk to your healthcare provider about your risks if you are in one of these age groups.

What should I tell my healthcare provider before using olanzapine/fluoxetine?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if olanzapine/fluoxetine is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.

  • Heart problems, including blood pressure problems
  • Seizures
  • Diabetes or high blood sugar
  • High cholesterol or triglyceride levels
  • Liver problems
  • Alzheimer’s disease
  • Stroke or mini-stroke
  • Bleeding problems
  • Difficulty emptying your bladder, including prostate problems
  • Constipation
  • A gut blockage (bowel obstruction) or slow digestion/movement in the gut
  • Breast cancer
  • Glaucoma or untreated narrow angles in the eye
  • Thoughts of suicide

Psychosis Related to Dementia. There is a higher risk of death, stroke, or mini-stroke in older adults who take olanzapine/fluoxetine or another antipsychotic and have memory loss or psychosis related to dementia. Olanzapine/fluoxetine is not approved to treat dementia-related psychosis.

Pregnancy. Taking olanzapine/fluoxetine later in pregnancy may lead to an increased risk of certain problems in your unborn baby. Tell your healthcare provider if you are or plan to become pregnant. Your healthcare provider will advise you if you should take olanzapine/fluoxetine while you are pregnant or trying to get pregnant. If you become pregnant while taking olanzapine/fluoxetine, you can register with the National Pregnancy Registry for Atypical Antipsychotics by calling 866-961-2388 or at womensmentalhealth.org/research/pregnancyregistry. This registry collects safety information about the use of psychiatric medicines during pregnancy.

Breastfeeding. Olanzapine/fluoxetine passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should take olanzapine/fluoxetine while breastfeeding.

Interactions

Does olanzapine/fluoxetine interact with foods or drinks?

There are no known interactions between olanzapine/fluoxetine and foods or drinks.

Avoid drinking alcohol while taking olanzapine/fluoxetine. Drinking alcohol while taking olanzapine/fluoxetine could increase your risk of difficulty paying attention, drowsiness, tiredness, or a drop in blood pressure upon standing.

Does olanzapine/fluoxetine interact with other medicines (drug interactions)?

Olanzapine/fluoxetine interacts with many other medicines. Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, other supplements or therapies you are using.

In particular, make sure that you discuss if you are using any of the following before taking olanzapine/fluoxetine.

  • Any other medicine that has olanzapine or fluoxetine in it
  • A monoamine oxidase inhibitor (MAOI) within the past 2 weeks, which is a medicine usually used for depression or Parkinson’s disease
  • Pimozide, thioridazine, or any other antipsychotic, which is a medicine for certain mental health conditions 
  • A tricyclic antidepressant, such as amitriptyline, nortriptyline, or protriptyline, even if it is not used for depression
  • A medicine for high blood pressure
  • A selective serotonin reuptake inhibitor (SSRI) or serotonin and norepinephrine reuptake inhibitor (SNRI), which is a medicine commonly used for anxiety and depression
  • A triptan, such as sumatriptan (Imitrex and others), eletriptan (Relpax), and others, which is a medicine commonly used to treat migraines
  • An opioid, such as oxycodone, morphine, codeine, tramadol, or fentanyl, which is a medicine used for certain types of pain
  • Lithium or buspirone, which is a medicine for certain mental health conditions
  • A stimulant, such as methylphenidate, lisdexamfetamine, or amphetamine, which is a medicine commonly used to treat attention deficit hyperactivity disorder (ADHD)
  • Tryptophan or St. John’s wort, which is a supplement
  • Aspirin or a nonsteroidal anti-inflammatory drug (NSAID), such as ibuprofen, naproxen, and others, which is in many prescription and OTC products for pain, swelling, and fever
  • Warfarin, which is a blood thinner
  • A benzodiazepine, such as clonazepam (Klonopin), diazepam (Valium and others), or lorazepam (Ativan and others), which is a medicine used for anxiety, muscle spasms, or seizure
  • Digoxin or any other medicine used to control your heart rate or rhythm (antiarrhythmic)
  • Valproic acid, phenytoin, or carbamazepine, which is a medicine used for seizures and other conditions
  • A dopamine agonist, such as pramipexole (Mirapex ER), ropinirole, rotigotine (Neupro), or apomorphine (Apokyn) or levodopa, which is a medicine that may be used for Parkinson’s disease
  • Fluvoxamine (Luvox), which is a medicine commonly used for obsessive-compulsive disorder (OCD)
  • Medicines that can cause QT prolongation, which is a potentially dangerous heart rhythm problem, such as tacrolimus
  • An anticholinergic medicine, which includes antihistamines and medicines commonly used for overactive bladder, Parkinson’s disease, or stomach problems
  • Any other medicine that causes dizziness and sleepiness, such as prescription pain medicines, sleep medicines, and medicines for anxiety
  • Electroconvulsive therapy (ECT)

Many other medicines may alter the blood levels of olanzapine/fluoxetine, and vice versa. Tell your healthcare provider about all medicines that you take or have recently taken.

This may not be a complete list of medicines that can interact with olanzapine/fluoxetine. Always check with your healthcare provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much olanzapine/fluoxetine?

If you or someone else has used too much olanzapine/fluoxetine, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of olanzapine/fluoxetine?

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses.