Fluoxetine
An SSRI antidepressant used for depression, anxiety, and bulimia.
Fluoxetine, best known by the brand name Prozac, is a medication in the selective serotonin reuptake inhibitor (SSRI) class, primarily used to treat depression and several other psychiatric conditions. It was invented by Eli Lilly and Company in 1972, and the company filed a new drug application with the US Food and Drug Administration in 1974, which was accepted in 1977. The drug entered medical use in 1986. It is taken by mouth and is available as a generic medication, appearing on the World Health Organization's List of Essential Medicines. In 2023, it was the eighteenth most commonly prescribed medication in the United States and the fourth most common antidepressant, with over 27 million prescriptions. Eli Lilly also markets a fixed-dose combination of fluoxetine with olanzapine, known as olanzapine/fluoxetine (Symbyax), which was approved by the FDA for depressive episodes of bipolar I disorder in 2003 and for treatment-resistant depression in 2009.
Common side effects include loss of appetite, nausea, diarrhea, headache, trouble sleeping, dry mouth, and sexual dysfunction. In some patients, sexual dysfunction may persist after stopping the drug, a condition known as post-SSRI sexual dysfunction. Serious side effects can include serotonin syndrome, mania, seizures, an increased risk of suicidal behavior, and an increased risk of bleeding. Fluoxetine is approved for major depressive disorder in adults and in children aged eight and older. It is also used for obsessive–compulsive disorder, panic disorder, premenstrual dysphoric disorder, bulimia nervosa, and has been used to treat premature ejaculation. Studies have shown it can reduce low-intensity aggressive behavior in conditions such as intermittent explosive disorder and borderline personality disorder, and it has also reduced domestic violence in alcoholics with a history of such behavior.
- class
- Selective serotonin reuptake inhibitor (SSRI)
- common brand
- Prozac
- manufacturer
- Eli Lilly and Company
- prescriptions (2023)
- over 27 million in the United States
Lore & Background
Fluoxetine, best known under the brand name Prozac, is an antidepressant belonging to the selective serotonin reuptake inhibitor (SSRI) class. It is taken orally and is used to treat major depressive disorder, obsessive-compulsive disorder, panic disorder, premenstrual dysphoric disorder, and bulimia nervosa, among other conditions. It is also approved for use in children aged eight and older for major depression. The drug was developed by Eli Lilly and Company in 1972, with a new drug application filed in 1974 and accepted in 1977; it entered medical use in 1986. Common side effects include loss of appetite, nausea, diarrhea, headache, insomnia, dry mouth, and sexual dysfunction, which may persist after discontinuation in some cases (post-SSRI sexual dysfunction). Serious risks include serotonin syndrome, mania, seizures, increased suicidal behavior, and bleeding. Fluoxetine is available as a generic medication and appears on the World Health Organization's List of Essential Medicines. In 2023, it was the eighteenth most prescribed medication in the United States and the fourth most common antidepressant, with over 27 million prescriptions. Eli Lilly also markets a fixed-dose combination with olanzapine (Symbyax) for bipolar I disorder depressive episodes and treatment-resistant depression.
Reader's Guide
Fluoxetine is significant as one of the first SSRIs and remains widely prescribed for major depressive disorder, OCD, panic disorder, bulimia nervosa, and premenstrual dysphoric disorder. It is considered the most stimulating of the SSRIs, often causing insomnia and agitation. Despite this, it remains a first-line medication for impulsive aggression and for children and adolescents with moderate-to-severe depression, though evidence for the latter is of dubious quality. It is also used off-label for premature ejaculation and has shown initial promise for reducing COVID-19 severity if given early.
Did You Know?
- Common side effects include loss of appetite, nausea, diarrhea, headache, trouble sleeping, dry mouth, and sexual dysfunction; sexual dysfunction may persist after discontinuation (post-SSRI sexual dysfunction).
- Fluoxetine is considered the most stimulating of the SSRIs, most prone to causing insomnia and agitation.
Frequently Asked Questions
Who is Fluoxetine?
Fluoxetine is the generic name for a selective serotonin reuptake inhibitor (SSRI) antidepressant most widely recognized by its brand name Prozac. It was developed by Eli Lilly and Company and has been a cornerstone of psychiatric pharmacology since the mid-1980s.
What conditions does Fluoxetine treat?
It is prescribed for major depressive disorder, various anxiety presentations, obsessive-compulsive disorder, panic disorder, premenstrual dysphoric disorder, and bulimia nervosa. It is also one of the few antidepressants cleared for use in adolescents and children aged eight and older.
Why does Fluoxetine matter in the broader pharmacology canon?
As one of the earliest widely adopted SSRIs, it helped shift psychiatric treatment away from older tricyclic agents toward a class of drugs with a generally more favorable side-effect profile. Its long track record of safety data across age groups and multiple diagnoses makes it a benchmark against which newer antidepressants are often compared.
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