Fluoxetine is used to treat depression, obsessive-compulsive disorder (OCD), bulimia nervosa, premenstrual dysphoric disorder (PMDD), and panic disorder. It is also used together with olanzapine to treat depression that is part of bipolar disorder.

Fluoxetine is an antidepressant and belongs to a group of medicines known as selective serotonin reuptake inhibitors (SSRIs). This medicine works by increasing the activity of a chemical called serotonin in the brain.

This medicine is available only with your doctor's prescription.

Take this medicine only as directed by your doctor, to benefit your condition as much as possible. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.

This medicine should come with a Medication Guide. It is very important that you read and understand this information. Be sure to ask your doctor about anything you do not understand.

You may take the medicine with or without food.

For some conditions, it may take a month or longer before you begin to feel better. If you feel that the medicine is not working well, tell your doctor right away.

If you are using the oral liquid, shake the bottle well before measuring each dose. Measure the liquid with a marked measuring spoon, oral syringe, or medicine cup. A regular household teaspoon will not measure the proper amount of medicine.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

Hives, itching, or skin rash

inability to sit still

restlessness

Less common

Chills or fever

joint or muscle pain

Rare

Anxiety

cold sweats

confusion

convulsions (seizures)

cool pale skin

diarrhea

difficulty with concentration

drowsiness

dryness of the mouth

excessive hunger

fast or irregular heartbeat

headache

increased sweating

increased thirst

lack of energy

mood or behavior changes

overactive reflexes

purple or red spots on the skin

racing heartbeat

shakiness or unsteady walk

shivering or shaking

talking, feeling, and acting with excitement and activity you cannot control

trouble with breathing

unusual or incomplete body or facial movements

unusual tiredness or weakness

Incidence not known

Abdominal or stomach pain

agitation

back or leg pains

bleeding gums

blindness

blistering, peeling, or loosening of the skin

bloating

blood in the urine or stools

bloody, black or tarry stools

blue-yellow color blindness

blurred vision

chest pain or discomfort

clay-colored stools

constipation

continuing vomiting

cough or dry cough

dark urine

decreased urine output

decreased vision

depression

difficulty with breathing

difficulty with swallowing

dizziness or lightheadedness

eye pain

fainting

fast, pounding, or irregular heartbeat or pulse

general body swelling

high fever

hives, itching, puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue

hostility

indigestion

irregular or slow heart rate

irritability

large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs

light-colored stools

loss of appetite

loss of bladder control

muscle twitching

nausea

nightmares

no blood pressure or pulse

noisy breathing

nosebleeds

pain in the ankles or knees

painful, red lumps under the skin, mostly on the legs

pains in the stomach, side, or abdomen, possibly radiating to the back

pinpoint red spots on the skin

rapid weight gain

red or irritated eyes

red skin lesions, often with a purple center

redness, tenderness, itching, burning, or peeling of the skin

severe muscle stiffness

severe sleepiness

slurred speech

sore throat

sores, ulcers, or white spots on the lips or in the mouth

stopping of heart

sudden shortness of breath or troubled breathing

sudden weakness in the arms or legs

sudden, severe chest pain

swelling of the face, ankles, or hands

swollen or painful glands

thoughts of killing oneself

tightness in the chest

tiredness

twitching, twisting, or uncontrolled repetitive movements of the tongue, lips, face, arms, or legs

unconsciousness

unpleasant breath odor

unusual bleeding or bruising

unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness

unusually pale skin

use of extreme physical or emotional force

vomiting of blood

yellow eyes or skin

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Decreased appetite

Less common or rare

Abnormal dreams

breast enlargement or pain

change in sense of taste

changes in vision

feeling of warmth or heat

flushing or redness of the skin, especially on face and neck

frequent urination

hair loss

increased appetite

increased sensitivity of the skin to sunlight

menstrual pain

stomach cramps, gas, or pain

unusual secretion of milk, in females

weight loss

yawning

Incidence not known

Cracks in the skin

loss of heat from the body

painful or prolonged erections of the penis

scaly skin

swelling of the breasts or breast soreness in both females and males

unusual milk production

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

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

It is important that your doctor check your progress at regular visits, to allow changes in your dose and help reduce any side effects. Blood tests may be needed to check for unwanted effects.

Do not take fluoxetine with a monoamine oxidase (MAO) inhibitor (eg, isocarboxazid [Marplan®], linezolid [Zyvox®], methylene blue injection, phenelzine [Nardil®], selegiline [Eldepryl®], tranylcypromine [Parnate®]). Do not start taking fluoxetine during the 2 weeks after you stop a MAO inhibitor and wait 5 weeks after stopping fluoxetine before you start taking a MAO inhibitor. If you take them together or do not wait the proper amount of time, you may develop confusion, agitation, restlessness, stomach or intestinal symptoms, a sudden high body temperature, an extremely high blood pressure, or severe convulsions.

Do not take thioridazine (Mellaril®) with fluoxetine and wait 5 weeks after stopping fluoxetine before you start taking thioridazine. Do not use pimozide (Orap®) with fluoxetine. Using these medicines together can cause very serious heart problems.

Fluoxetine may cause a serious condition called serotonin syndrome if taken together with some medicines. Do not use fluoxetine with buspirone (Buspar®), fentanyl (Abstral®, Duragesic®), lithium (Eskalith®, Lithobid®), tryptophan, St. John's wort, amphetamines, or some pain or migraine medicines (eg, rizatriptan, sumatriptan, tramadol, Frova®, Imitrex®, Maxalt®, Relpax®, Ultram®, Zomig®). Check with your doctor first before taking any other medicines with fluoxetine.

Fluoxetine may cause some teenagers and young adults to be agitated, irritable, or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed. Some people may have trouble sleeping, get upset easily, have a big increase in energy, or start to act reckless. If you or your caregiver notice any of these unwanted effects, tell your doctor right away. Let the doctor know if you or anyone in your family has bipolar disorder (manic-depressive) or has tried to commit suicide.

Do not suddenly stop taking this medicine without checking first with your doctor. Your doctor may want you to gradually reduce the amount you are using before stopping it completely. This will decrease the chance of having withdrawal symptoms such as agitation, breathing problems, chest pain, confusion, diarrhea, dizziness or lightheadedness, fast heartbeat, headache, increased sweating, muscle pain, nausea, restlessness, runny nose, trouble sleeping, trembling or shaking, unusual tiredness or weakness, vision changes, or vomiting.

Tell your doctor right away if you develop a rash or hives, swelling of the face, eyes, or mouth, or trouble breathing after taking this medicine.

This medicine may increase your risk for bleeding problems. Make sure your doctor knows if you are also taking other medicines that thin the blood, such as aspirin, nonsteroidal antiinflammatory agents, also called NSAIDs (eg, diclofenac, ibuprofen, naproxen, Advil®, Aleve®, Celebrex®, Voltaren®), or warfarin (Coumadin®, Jantoven®).

Hyponatremia (low sodium in the blood) may occur with this medicine. Check with your doctor right away if you have confusion, difficulty concentrating, headaches, memory problems, weakness, and unsteadiness.

Contact your doctor right away if you have dizziness, fainting, or a fast, pounding, or uneven heartbeat. Make sure your doctor knows if you have ever had a heart rhythm problem, such as QT prolongation, or if you or a family member has had a heart attack, heart failure, low blood pressure, or a stroke.

The use of alcohol is not recommended in patients who are taking fluoxetine.

This medicine may affect blood sugar levels. If you are diabetic and notice a change in the results of your blood or urine sugar tests, check with your doctor.

This medicine may cause some people to become drowsy or less able to think clearly, or to have poor muscle control. Make sure you know how you react to fluoxetine before you drive, use machines, or do anything else that could be dangerous if you are not alert and well able to control your movements.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.