Why is this medication prescribed?
Fluoxetine (Flunil or Prozac) is used to treat depression, obsessive-compulsive disorder (bothersome thoughts that won’t go away and the need to perform certain actions over and over), some eating disorders, and panic attacks (sudden, unexpected attacks of extreme fear and worry about these attacks). Fluoxetine (Sarafem) is used to relieve the symptoms of premenstrual dysphoric disorder, including mood swings, irritability, bloating, and breast tenderness. It is also used along with olanzapine (Zyprexa) to treat depression that did not respond to other medications and episodes of depression in people with bipolar I disorder (manic-depressive disorder; a disease that causes episodes of depression, episodes of mania, and other abnormal moods). Fluoxetine is in a class of medications called selective serotonin reuptake inhibitors (SSRIs). It works by increasing the amount of serotonin, a natural substance in the brain that helps maintain mental balance.
How should this medicine be used?
Fluoxetine (Flunil or Prozac) comes as a capsule, a tablet, a delayed-release (releases the medication in the intestine) capsule, and a solution (liquid) to take by mouth. Fluoxetine may be taken with or without food. Fluoxetine capsules, tablets, and liquid are usually taken once a day in the morning or twice a day in the morning and at noon. Fluoxetine delayed-released capsules are usually taken once a week. Take fluoxetine at around the same time(s) every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take fluoxetine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Your doctor may start you on a low dose of fluoxetine and gradually increase your dose.
It may take 4 to 5 weeks or longer before you feel the full benefit of fluoxetine. Continue to take fluoxetine even if you feel well. Do not stop taking fluoxetine without talking to your doctor. If you suddenly stop taking fluoxetine, you may experience withdrawal symptoms such as mood changes, irritability, agitation, dizziness, numbness or tingling in the hands or feet, anxiety, sweating, confusion, headache, tiredness, and difficulty falling asleep or staying asleep. Your doctor will probably decrease your dose gradually.
Other uses for this medicine
Fluoxetine is also sometimes used to treat alcoholism, attention-deficit disorder, borderline personality disorder, sleep disorders, headaches, mental illness, posttraumatic stress disorder, Tourette’s syndrome, obesity, sexual problems, and phobias. Talk to your doctor about the possible risks of using this medication for your condition.
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
What special precautions should I follow?
Before taking fluoxetine,
- tell your doctor and pharmacist if you are allergic to fluoxetine, any other medications, or any of the ingredients in fluoxetine preparations. Ask your pharmacist for a list of the ingredients.
- tell your doctor if you are taking pimozide (Orap), thioridazine, or a monoamine oxidase (MAO) inhibitor such as isocarboxazid (Marplan), linezolid (Zyvox), methylene blue, phenelzine (Nardil), selegiline (Eldepryl, Emsam, Zelapar), and tranylcypromine (Parnate), or if you have stopped taking a monoamine oxidase inhibitor within the past 2 weeks. Your doctor will probably tell you that you should not take fluoxetine. If you stop taking fluoxetine, you should wait at least 5 weeks before you begin to take thioridazine or a monoamine oxidase inhibitor.
- tell your doctor and pharmacist what other prescription and nonprescription medications and vitamins you are taking or plan to take. Be sure to mention any of the following: alprazolam (Xanax); amiodarone (Pacerone, Nexterone); certain antibiotics such as erythromycin (E.E.S, Eryc, Ery-tab), gatifloxacin, moxifloxacin (Avelox), and sparfloxacin (no longer available in U.S., Zagam); amphetamines such as amphetamine (in Adderall), dextroamphetamine (Dexedrine, Dextrostat, in Adderall), and methamphetamine (Desoxyn); anticoagulants (‘blood thinners’) such as warfarin (Coumadin, Jantoven); antidepressants (mood elevators) such as amitriptyline (Elavil), amoxapine, clomipramine (Anafranil), desipramine (Norpramin), doxepin, imipramine (Tofranil), nortriptyline (Pamelor), protriptyline (Vivactil), and trimipramine (Surmontil); aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil, Motrin) and naproxen (Aleve, Naprosyn); buspirone; clopidogrel (Plavix); diazepam (Valium); digoxin (Lanoxin); diuretics (‘water pills’); dolasetron (Anzemet); fentanyl (Duragesic, Lazanda, Subsys, others); flecainide (Tambocor); insulin or oral medications for diabetes; lithium (Lithobid); medications for anxiety and Parkinson’s disease; medications for mental illness such as chlorpromazine, clozapine (Clozaril, Versacloz), droperidol (Inapsine), haloperidol (Haldol), iloperidone (Fanapt), and ziprasidone (Geodon); methadone (Methadose); medications for migraine headaches such as almotriptan (Axert), eletriptan (Relpax), frovatriptan (Frova), naratriptan (Amerge), rizatriptan (Maxalt), sumatriptan (Imitrex), and zolmitriptan (Zomig); pentamidine (Pentam); quinidine (in Nuedexta); procainamide; medications for seizures such as carbamazepine (Epitol, Tegretol, Teril) and phenytoin (Dilantin, Phenytek); sedatives; sleeping pills; other selective serotonin-reuptake inhibitors such as citalopram (Celexa), fluoxetine (Prozac, Sarafem, Selfemra), or fluvoxamine (Luvox); serotonin–norepinephrine reuptake inhibitors (SNRI) medications desvenlafaxine (Khedezla, Pristiq), duloxetine (Cymbalta), levomilnacipran (Fetzima), and venlafaxine; sotalol (Betapace, Sorine); tramadol (Ultram); tranquilizers; and vinblastine (Velban). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
- tell your doctor what nutritional supplements and herbal products you are taking, especially products that contain St. John’s wort or tryptophan.
- tell your doctor if you or anyone in your family has or has ever had a prolonged QT interval (a rare heart problem that may cause irregular heartbeat, fainting, or sudden death). Also tell your doctor if you have a low level of potassium or magnesium in your blood or are being treated with electroshock therapy (procedure in which small electric shocks are administered to the brain to treat certain mental illnesses). Tell your doctor if you have recently had a heart attack and if you have or have ever had heart failure, diabetes, seizures, or liver or heart disease.
- tell your doctor if you are pregnant, especially if you are in the last few months of your pregnancy, or if you plan to become pregnant or are breastfeeding. If you become pregnant while taking fluoxetine, call your doctor. Fluoxetine may cause problems in newborns following delivery if it is taken during the last months of pregnancy.
- you should know that fluoxetine may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.
- remember that alcohol can add to the drowsiness caused by this medication.
- you should know that fluoxetine may cause angle-closure glaucoma (a condition where the fluid is suddenly blocked and unable to flow out of the eye causing a quick, severe increase in eye pressure which may lead to a loss of vision). Talk to your doctor about having an eye examination before you start taking this medication. If you have nausea, eye pain, changes in vision, such as seeing colored rings around lights, and swelling or redness in or around the eye, call your doctor or get emergency medical treatment right away.
What should I do if I forget a dose?
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
What side effects can this medication cause?
Fluoxetine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- difficulty falling asleep or staying asleep
- dry mouth
- uncontrollable shaking of a part of the body
- loss of appetite
- weight loss
- changes in sex drive or ability
- excessive sweating
- headache, confusion, weakness, difficulty concentrating, or memory problems
Some side effects can be serious. If you experience any of the following symptoms or those listed in the IMPORTANT WARNING or SPECIAL PRECAUTIONS section, call your doctor immediately:
- hives or blisters
- joint pain
- swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
- difficulty breathing or swallowing
- agitation, fever, sweating, confusion, fast or irregular heartbeat, shivering, severe muscle stiffness or twitching, hallucinations, loss of coordination, nausea, vomiting, or diarrhea
- fast, slow, or irregular heartbeat
- shortness of breath
- dizziness or fainting
- abnormal bleeding or bruising
Fluoxetine may decrease appetite and cause weight loss in children. Your child’s doctor will watch his or her growth carefully. Talk to your child’s doctor if you have concerns about your child’s growth or weight while he or she is taking this medication. Talk to your child’s doctor about the risks of giving fluoxetine to your child.
Fluoxetine may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).
What should I know about storage and disposal of this medication?
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from light, excess heat, and moisture (not in the bathroom).
Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA’s Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.
It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org
In case of emergency/overdose
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can’t be awakened, immediately call emergency services at 911.
Symptoms of overdose may include the following:
- uncontrollable shaking of a part of the body
- rapid, irregular, or pounding heartbeat
- seeing things or hearing voices that do not exist (hallucinating)
- coma (loss of consciousness for a period of time)
What other information should I know?
Keep all appointments with your doctor.
Before having any laboratory test (especially those that involve methylene blue), tell your doctor and the laboratory personnel that you are taking fluoxetine.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
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