Fluoxetine (Systemic)

Brand name(s): Prozac

Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For fluoxetine, the following should be considered:

Allergies-Tell your doctor if you have ever had any unusual or allergic reaction to fluoxetine. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy-One study of babies whose mothers had taken fluoxetine while they were pregnant found some problems in the babies, such as premature birth, jitteriness, and trouble in breathing or nursing. However, four other studies did not find any problems in babies or young children whose mothers had taken fluoxetine while they were pregnant. Tell your doctor if you are pregnant (especially if it is the third trimester) or if you may become pregnant while you are taking this medicine.

Breast-feeding-Fluoxetine passes into breast milk. A study of 11 breast-fed babies whose mothers were taking fluoxetine found no effect on the babies. However, another baby whose mother was taking this medicine had vomiting, watery stools, crying, and sleep problems. Be sure you have discussed the risks and benefits of this medicine with your doctor.

Children-This medicine has been tested in a limited number of children 7 to 18 years of age. These studies indicate that fluoxetine may help to treat depression and obsessive-compulsive disorder in children. However, unusual excitement, restlessness, irritability, and trouble in sleeping may be especially likely to occur in children, who seem to be more sensitive than adults to the effects of fluoxetine. Fluoxetine must be used with caution in children with depression. Studies have shown occurrences of children thinking about suicide or attempting suicide in clinical trials for this medicine. More study is needed to be sure fluoxetine is safe and effective in children.

Older adults-Many medicines have not been tested in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. In studies done to date that included elderly people, fluoxetine did not cause different side effects or problems in older people than it did in younger adults.

Other medicines-Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking fluoxetine, it is especially important that your health care professional know if you are taking any of the following:

• Alprazolam (e.g., Xanax)-Higher blood levels of alprazolam may occur and its effects may be increased

• Anticoagulants (blood thinners) (warfarin [e.g., Coumadin) or
• Digitalis glycosides (heart medicine)-Higher or lower blood levels of these medicines or fluoxetine may occur, increasing the chance of unwanted effects such as serious bleeding problems. Your doctor may need to see you more often, especially when you first start or when you stop taking fluoxetine. Your doctor also may need to change the dose of either medicine

• Aspirin or
• Nonsteroidal anti-inflammatory drugs (NSAIDs) (celecoxib [e.g., Celebrex], diclofenac [e.g., Voltaren], diflunisal [e.g., Dolobid], etodolac [e.g., Lodine], fenoprofen [e.g., Nalfon], flurbiprofen [e.g., Ansaid], ibuprofen [e.g., Advil, Motrin, Nuprin], indomethacin [e.g., Indocin], ketoprofen [e.g., Orudis, Oruvail], ketorolac [e.g., Toradol], meclofenamate [e.g., Meclomen], mefenamic acid [e.g., Ponstel], meloxicam [e.g., Mobic], nabumatone [e.g., Relafen], naproxen [e.g., Aleve, Anaprox, Naprosyn], oxaprozin [e.g., Daypro], phenylbutazone, piroxicam [e.g., Feldene], rofecoxib [e.g., Vioxx], sulindac [e.g., Clinoril], tolmetin [e.g., Tolectin], valdecoxib [e.g., Bextra])-Taking any of these medicines with fluoxetine may cause bleeding problems.

• Astemizole (e.g., Hismanal)-Higher blood levels of astemizole may occur, which increases the chance of having a very serious change in the rhythm of your heartbeat

• Buspirone (e.g., BuSpar) or
• Bromocriptine (e.g., Parlodel) or
• Dextromethorphan (cough medicine) or
• Levodopa (e.g., Sinemet) or
• Lithium (e.g., Eskalith) or
• Meperidine (e.g., Demerol) or
• Nefazodone (e.g., Serzone) or
• Pentazocine (e.g., Talwin) or
• Selective serotonin reuptake inhibitors, other (citalopram [Celexa], fluvoxamine [e.g., Luvox], paroxetine [e.g., Paxil], sertraline [e.g., Zoloft]) or
• Street drugs (LSD, MDMA [e.g., ecstasy], marijuana) or
• Sumatriptan (e.g., Imitrex) or
• Tramadol (e.g., Ultram) or
• Trazodone (e.g., Desyrel) or
• Tryptophan or
• Venlafaxine (e.g., Effexor)-Using these medicines with fluoxetine or within 5 weeks of stopping fluoxetine may increase the chance of developing a rare, but very serious, unwanted effect known as the serotonin syndrome. This syndrome may cause confusion, diarrhea, fever, poor coordination, restlessness, shivering, sweating, talking or acting with excitement you cannot control, trembling or shaking, or twitching. If you develop these symptoms contact your doctor as soon as possible. Taking tramadol with fluoxetine increases the chance of having convulsions (seizures). Also, taking tryptophan with fluoxetine may result in increased agitation or restlessness and intestinal or stomach problems

• Moclobemide (e.g., Manerex)-The risk of developing serious unwanted effects, including the serotonin syndrome, is increased. Use of moclobemide with fluoxetine is not recommended. Also, it is recommended that 7 days be allowed between stopping treatment with moclobemide and starting treatment with fluoxetine, and it is recommended that 5 weeks be allowed between stopping treatment with fluoxetine and starting treatment with moclobemide

• Monoamine oxidase (MAO) inhibitor activity (isocarboxazid [e.g., Marplan], phenelzine [e.g., Nardil], procarbazine [e.g., Matulane], selegiline [e.g., Eldepryl], tranylcypromine [e.g., Parnate])- Do not take fluoxetine while you are taking or within 2 weeks of taking an MAO inhibitor. If you do, you may develop confusion, agitation, restlessness, stomach or intestinal problems, sudden high body temperature, extremely high blood pressure, and severe convulsions. At least 14 days should be allowed between stopping treatment with an MAO inhibitor and starting treatment with fluoxetine. If you have been taking fluoxetine, at least 5 weeks should be allowed between stopping treatment with fluoxetine and starting treatment with an MAO inhibitor

• Phenytoin (e.g., Dilantin) or
• Tricyclic antidepressants (amitriptyline [e.g., Elavil], amoxapine [e.g., Asendin], clomipramine [e.g., Anafranil], desipramine [e.g., Pertofrane], doxepin [e.g., Sinequan], imipramine [e.g., Tofranil], nortriptyline [e.g., Aventyl], protriptyline [e.g., Vivactil], trimipramine [e.g., Surmontil])-Higher blood levels of these medicines may occur, which increases the chance of having serious side effects. Your doctor may want to see you more often and may need to change the doses of your medicines. Also, taking amitriptyline, clomipramine, or imipramine with fluoxetine may increase the chance of developing the serotonin syndrome

• Thioridazine (e.g., Mellaril)-Taking thioridazine with fluoxetine can cause serious heart problems.

Other medical problems-The presence of other medical problems may affect the use of fluoxetine. Make sure you tell your doctor if you have any other medical problems, especially:

• Bipolar disorder (mood disorder with alternating episodes of mania and depression) or risk of-May make condition worse. Your doctor will check you for this condition.

• Brain disease or mental retardation or
• Seizures, history of-The chance of having seizures may be increased

• Diabetes-The amount of insulin or oral antidiabetic medicine that you need to take may change

• Diseases that affect your body's metabolism-Caution should be used

• Kidney disease or
• Liver disease-Higher blood levels of fluoxetine may occur, increasing the chance of side effects

• Parkinson's disease-May become worse

• Weight loss-Fluoxetine may cause weight loss. This weight loss is usually small, but if a large weight loss occurs, it may be harmful in some patients

Last Revised: 02/01/2005