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Treatments > Medications Used In MS

Brand Name Chemical Name

(U.S. and Canada)


Primary Usage in MS

Generic Available
Depression; Fatigue Yes

Fluoxetine is used to treat mental depression and panic disorder. It is also used occasionally to treat MS fatigue.

Proper Usage
This medication should be taken in the morning when used to treat depression because it can interfere with sleep. If it upsets your stomach, you may take it with food.

It may take four to six weeks for you to feel the beneficial effects of this medication.

Your physician should monitor your progress at regularly scheduled visits in order to adjust the dose and help reduce any side effects.

There have been suggestions that the use of fluoxetine may be related to increased thoughts about suicide in a very small number of individuals. More study is needed to determine if the medicine causes this effect. If you have concerns about this, be sure to discuss them with your physician.

Fluoxetine adds to the effects of alcohol and other central nervous system depressants (e.g., antihistamines, sedatives, tranquilizers, sleeping medicine, prescription pain medicine, barbiturates, seizure medication, muscle relaxants). Be sure that your physician knows if you are taking these or any other medications.

This medication affects the blood sugar levels of diabetic individuals. Check with your physician if you notice any changes in your blood or urine sugar tests.

Dizziness or lightheadedness may occur, especially when you get up from a lying or sitting position. Change positions slowly to help alleviate this problem. If the problem continues or gets worse, consult your physician.

Fluoxetine may cause dryness of the mouth. If your mouth continues to feel dry for more than two weeks, check with your physician or dentist. Continuing dryness of the mouth may increase the chance of dental disease.

Studies have not been done in pregnant women. Fluoxetine has not been shown to cause birth defects or other problems in animal studies.

Fluoxetine passes into breast milk and may cause unwanted effects, such as vomiting, watery stools, crying, and sleep problems in nursing babies. You may want to discuss alternative medications with your physician.

Possible Side Effects
Side effects that may go away as your body adjusts to the medication and do not require medical attention unless they continue for several weeks or are bothersome: decreased sexual drive or ability*; anxiety and nervousness; diarrhea; drowsiness*; headache; trouble sleeping; abnormal dreams; change in vision*; chest pain; decreased appetite; decrease in concentration; dizziness; dry mouth; fast or irregular heartbeat; frequent urination*; menstrual pain; tiredness or weakness*; tremor*; vomiting.

Unusual side effects that should be discussed with your physician as soon as possible: chills or fever; joint or muscle pain; skin rash; hives or itching; trouble breathing.

Symptoms of overdose that require immediate medical attention: agitation and restlessness; convulsions; severe nausea and vomiting; unusual excitement.

*Since it may be difficult to distinguish between certain common symptoms of MS and some side effects of fluoxetine, be sure to consult your health care professional if an abrupt change of this type occurs.

Medication Index

Other Medications Used to Treat Depression

Other Medications Used to Treat MS-related Fatigue

About Depression

About Antidepressants

Depression and MS
Therapies, resources, and more.

About Fatigue

Fatigue: What You Should Know
Causes and types of MS-related fatigue, therapies, personal stories, and more.

Reprinted with permission from Rosalind C. Kalb (ed.), Multiple Sclerosis: The Questions You Have—The Answers You Need, 3rd Edition. New York: Demos Medical Publishing, Inc., 2004

Last updated November 9, 2005