Side Effects of Prozac (Fluoxetine) for Bipolar Disorder

Bipolar Medications Library

Side effects of Prozac
Prozac capsule. Jonathan Nourok Collection/The Image Bank/Getty Images

Prozac (fluoxetine) is a selective serotonin reuptake inhibitor (SSRI), which is a class of antidepressant medication that may be prescribed for the treatment of depression, bipolar disorder and other mental illnesses. The side effects are wide-ranging from minor to serious. If you are taking Prozac, you should be aware of the potential side effects.

Common Side Effects of Prozac

Check with your doctor if any of the following Prozac side effects don't go away or are bothersome:

  • Anxiety or nervousness
  • Changes in sex drive
  • Decreased appetite
  • Diarrhea
  • Drowsiness
  • Headache
  • Increased sweating
  • Nausea
  • Sweating more than normal
  • Tiredness or weakness
  • Trembling or shaking
  • Trouble sleeping

Rare Side Effects of Prozac

These side effects are less common and include:

  • Abnormal dreams
  • Change in sense of taste
  • Changes in vision
  • Chest pain
  • Constipation
  • Dizziness or lightheadedness
  • Dryness of mouth
  • Flushing or redness of skin, especially on face and neck
  • Frequent urination
  • Hair loss
  • Increased appetite
  • Stomach cramps, gas, or pain; vomiting

Let Your Doctor Know About These Side Effects

If you have any of the following side effects, be sure to let your doctor know right away. They include:

  • Skin rash, hives, or itching
  • Chills or fever
  • Hallucinations
  • Joint or muscle pain or stiffness
  • Seizures
  • Trouble breathing or swallowing
  • Swelling in your face, throat, tongue, lips, eyes, hands, feet, ankles or lower legs
  • Symptoms of serotonin syndrome

    Possible Withdrawal Effects of Prozac

    Never go off of Prozac without speaking with your doctor first and tapering off gradually. If you have any of these withdrawal effects, contact your doctor:

    • Anxiety
    • Dizziness
    • Feeling that body or surroundings are turning
    • General feeling of discomfort or illness
    • Headache
    • Nausea
    • Sweating
    • Unusual tiredness or weakness

    Prozac Overdose Effects

    These effects may be more severe than the side effects you experience at the regular dose, or several side effects may occur together. Contact your doctor if you experience any of these effects, including:

    • Agitation and restlessness
    • Convulsions (seizures)
    • Drowsiness
    • Fast heartbeat
    • Nausea and vomiting
    • Talking, feeling, and acting with excitement and activity you cannot control
    • Trembling or shaking

    Other side effects not listed above may also occur in some patients taking Prozac. If you notice any other side effects, check with your doctor.

    Prozac for Bipolar Disorder

    The UK-based National Institute for Health and Care Excellence (NICE) put out an updated clinical guideline in late 2014 stating that Prozac (fluoxetine) is the only effective antidepressant for treating bipolar disorder, but only when used along with the antipsychotic Zyprexa (olanzapine). In the past, NICE had always recommended classes of medications as a whole and didn't target any specific kinds.

    Specifically, a study that NICE headed up showed that the combination of Prozac and Zyprexa was the most clinically helpful, as well as the most cost-effective. The study also found that other antidepressants alone were ineffective and that Zyprexa alone was effective, but more effective combined with Prozac.

    Symbyax: A Combination of Prozac and Zyprexa

    There is a medication that combines fluoxetine and olanzapine (Prozac and Zyprexa) called Symbyax that the U.S. Food and Drug Administration (FDA) approved for use in bipolar disorder in 2003 and for people with treatment-resistant depression in 2009.


    "Fluoxetine." MedLine Plus, U.S. National Library of Medicine, 2014.

    Lawrence, J. "Fluoxetine is the only antidepressant to be used in bipolar disorder, NICE says." The Pharmaceutical Journal 293 (7831), 2014.

    "Bipolar disorder: assessment and management." National Institute for Health and Care Excellence (2014).

    Hall-Flavin, D.K. "Bipolar disorder: Is treatment for bipolar I different from treatment for bipolar II?" Mayo Clinic (2015). 

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