Fluoxetine is used to treat depression, panic attacks, obsessive compulsive disorder, a certain eating disorder (bulimia), and a severe form of premenstrual syndrome (premenstrual dysphoric disorder).
This medication may improve your mood, sleep, appetite, and energy level and may help restore your interest in daily living. It may decrease fear, anxiety, unwanted thoughts, and the number of panic attacks. It may also reduce the urge to perform repeated tasks (compulsions such as hand-washing, counting, and checking) that interfere with daily living. Fluoxetine may lessen premenstrual symptoms such as irritability, increased appetite, and depression. It may decrease binging and purging behaviors in bulimia.
How to use Prozac
Read the Medication Guide provided by your pharmacist before you start using fluoxetine and each time you get a refill. If you have any questions, ask your doctor or pharmacist.
Take this medication by mouth as directed by your doctor, usually once daily in the morning. If you are taking this medication twice a day, your doctor may direct you to take it in the morning and at noon.
If you are taking fluoxetine for premenstrual problems, your doctor may direct you to take it every day of the month or just for the 2 weeks before your period through the first full day of your period. To help you remember, mark your calendar.
If you are using the liquid form of this medication, measure the dose carefully using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose.
The dosage is based on your medical condition and response to treatment. To reduce your risk of side effects, your doctor may direct you to start this medication at a low dose and gradually increase your dose. Follow your doctor’s instructions carefully. Take this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.
It is important to continue taking this medication as prescribed even if you feel well. Do not stop taking this medication without first consulting your doctor. Some conditions may become worse when the drug is abruptly stopped. Your dose may need to be gradually decreased.
You should see some improvement in 1 to 2 weeks. It may take 4 to 5 weeks before you feel the full benefit.
Tell your doctor if your condition does not improve or if it worsens.
See also Warning section.
Nausea, drowsiness, dizziness, anxiety, trouble sleeping, loss of appetite, tiredness, sweating, or yawning may occur. If any of these effects persist or worsen, tell your doctor promptly.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if you have any serious side effects, including: unusual or severe mental/mood changes (such as agitation, unusual high energy/excitement, thoughts of suicide), easy bruising/bleeding, muscle weakness/spasm, shakiness (tremor), decreased interest in sex, changes in sexual ability, unusual weight loss.
Get medical help right away if you have any very serious side effects, including: bloody/black/tarry stools, vomit that looks like coffee grounds, seizures, signs of kidney problems (such as change in the amount of urine), eye pain/swelling/redness, widened pupils, vision changes (such as seeing rainbows around lights at night, blurred vision).
If you have diabetes, fluoxetine may affect your blood sugar levels. Monitor your blood sugar regularly and share the results with your doctor. Your doctor may need to adjust your medication, diet, and exercise when you start or stop fluoxetine.
This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take (see Drug Interactions section). Get medical help right away if you develop some of the following symptoms: fast heartbeat, hallucinations, loss of coordination, severe dizziness, severe nausea/vomiting/diarrhea, twitching muscles, unexplained fever, unusual agitation/restlessness.
Rarely, males may have a painful or prolonged erection lasting 4 or more hours. If this occurs, stop using this drug and get medical help right away, or permanent problems could occur.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US –
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada – Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Before taking fluoxetine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: personal or family history of bipolar/manic-depressive disorder, personal or family history of suicide attempts, liver problems, diabetes, low sodium in the blood (such as may occur while taking “water pills” – diuretics), severe loss of body water (dehydration), seizures, stomach/intestinal ulcers, personal or family history of glaucoma (angle-closure type).
This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).
The liquid form of this medication contains alcohol. Caution is advised if you have diabetes, alcohol dependence, or liver disease. Some medications (such as metronidazole, disulfiram) can cause a serious reaction when combined with alcohol. Ask your doctor or pharmacist about using this product safely.
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Older adults may be more sensitive to the side effects of this drug, especially bleeding. Older adults may also be more likely to develop low sodium in the blood, especially if they are taking “water pills” (diuretics).
During pregnancy, this medication should be used only when clearly needed. It may harm an unborn baby. Also, babies born to mothers who have used this drug during the last 3 months of pregnancy may rarely develop withdrawal symptoms such as feeding/breathing difficulties, seizures, muscle stiffness, or constant crying. If you notice any of these symptoms in your newborn, tell the doctor promptly.
Since untreated mental/mood problems (such as depression, panic attacks, obsessive compulsive disorder) can be a serious condition, do not stop taking this medication unless directed by your doctor. If you are planning pregnancy, become pregnant, or think you may be pregnant, immediately discuss the benefits and risks of using this medication during pregnancy with your doctor.
This medication passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.