Description

Fluoxetine Hydrochloride (HCl) is an antidepressant medication that belongs to a class of drugs known as selective serotonin reuptake inhibitors (SSRIs). It is one of the most widely prescribed antidepressants globally and is available in various forms, including tablets, capsules, and an oral liquid solution. The most common brand name for fluoxetine is Prozac.

Indications

Fluoxetine HCl is used to treat a wide range of mental health and other medical conditions. Its primary indications include:

• Major Depressive Disorder (MDD): Used for both acute and long-term treatment of depression in adults and children.

• Obsessive-Compulsive Disorder (OCD): Approved for treating obsessions and compulsions in both adults and pediatric patients.

• Bulimia Nervosa: The only antidepressant specifically approved to treat binge-eating and purging behaviors.

• Panic Disorder: Used to manage panic attacks and associated symptoms.

• Premenstrual Dysphoric Disorder (PMDD): A severe form of premenstrual syndrome (PMS) with symptoms of depression and anxiety.
• Bipolar Depression: Often used in combination with other medications like olanzapine to treat depressive episodes.

Mechanism of Action

The therapeutic effect of fluoxetine is primarily attributed to its mechanism as a selective serotonin reuptake inhibitor (SSRI). Here’s how it works:

1. Serotonin’s Role: Serotonin is a neurotransmitter in the brain that plays a key role in regulating mood, emotion, sleep, and appetite. In many people with depression and anxiety disorders, serotonin levels are thought to be low.

2. Reuptake Process: Normally, after a nerve cell (neuron) releases serotonin into the space between neurons (the synaptic cleft), a reuptake pump on the presynaptic neuron reabsorbs the serotonin.

3. Fluoxetine’s Action: Fluoxetine works by blocking this reuptake pump. By inhibiting the reabsorption of serotonin, it allows the neurotransmitter to remain in the synaptic cleft for a longer period.

4. Increased Serotonin Levels: The resulting increase in serotonin concentration enhances its ability to bind to postsynaptic receptors, which helps to improve mood and emotional balance over time.

5. Long-Term Effects: This process leads to adaptive changes in the brain’s serotonin system, which are believed to be responsible for the long-term therapeutic benefits of the medication. Fluoxetine has a long half-life, meaning it stays in the body for an extended period, which contributes to its sustained effect.