Disclaimer: Human Health is not recommending any specific medical treatment for any particular symptom, nor providing any other medical advice. Always seek the advice of your doctor regarding any medical concern.

Indications

Fluoxetine is a medication approved by the FDA to treat a number of psychiatric conditions, including:

• Major depressive disorder (depression)
• Obsessive-compulsive disorder (OCD)
• Bulimia nervosa
• Panic disorder
• Post-traumatic stress disorder (PTSD)
• Social anxiety disorder
• Premenstrual dysphoric disorder (PMDD)

It is sometimes used to treat other conditions, including:

• Social anxiety disorder
• Post-traumatic stress disorder (PTSD) in adults
• Borderline personality disorder (BPD)
• Raynaud phenomenon
• Selective mutism

Fluoxetine may also be given in combination with other medications to treat other psychiatric conditions.

Brand names

Fluoxetine is available under a variety of different brand names, including:

• Prozac
• Fluotex
• Zactin
• Sarafem
• Symbyax

Formats

Fluoxetine is available as an oral capsule.

Approval

Fluoxetine was first approved for use as a medical treatment in 1997.

Drug class

Fluoxetine is an antidepressant. It is a particular type of antidepressant known as a selective serotonin reuptake inhibitor (SSRI).

Mechanism of action

Fluoxetine works by blocking the action of proteins in the brain called serotonin transporters. When serotonin transporters are deactivated, the amount of available serotonin in the brain increases.

Serotonin is a hormone that is involved in regulating processes such as mood, behavior, appetite, perception, fear and stress. Fluoxetine may also increase the levels of dopamine, another hormone that is involved in regulating mood and behavior.

Changing the level of serotonin and dopamine in the brain can therefore have an effect on conditions including depression and anxiety.

What’s the difference between fluoxetine and other antidepressants?

When determining an appropriate treatment plan, clinicians will consider a variety of factors relevant to the patient, including things like their age, the specific condition(s) they have, other treatments they are already on, and the side effects of the treatment.

Compared to other SSRIs, including escitalopram, sertraline, and citalopram, fluoxetine may be structurally different, may be effective at a different dose, and may be metabolized and excreted differently by the body.

Fluoxetine is indicated for bulimia nervosa, which some other SSRIs, including sertraline and escitalopram, are not approved to treat.

Fluoxetine is one of only a few antidepressants approved for use in pediatric patients with major depressive disorder, with the other being escitalopram.

Compared to some other classes of antidepressants, SSRIs like escitalopram may have fewer or less severe side effects.

Side effects

It is important to note that there may be increased risk for suicidal thinking and behavior in children, adolescents and young adults taking antidepressants for depression or other psychiatric disorders.

Fluoxetine may also make the heart beat faster or irregularly.

The most common side effects (>5% of patients) of fluoxetine include:

• Unusual dreams
• Sexual dysfunction
• Decreased libido
• Decreased appetite
• Feelings of anxiety
• Fatigue
• Sleepiness
• Increased sweating
• Yawning
• Inflammation of the mouth, throat, or sinuses
• Tremors
• Diarrhea
• Dry mouth
• Indigestion
• Flu-like symptoms (Fever, chills, headache, body aches)
• Insomnia
• Nausea
• Skin rash
• Skin flushing

Special instructions

The safety and action of fluoxetine has not been studied in children <8 with depression and in children <7 with OCD.

Patients taking another type of antidepressant called monoamine oxidase inhibitors (MOAIs) should not take fluoxetine.

Patients taking an antipsychotic drug called pimozide should not take fluoxetine.

Resources

1. Sohel AJ, Shutter MC, Molla M. Fluoxetine. [Updated 2022 Jul 4]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459223/
2. Prozac (fluoxetine hydrochloride) US Prescribing Information. 2023. Available from: https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=018936

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