Selective serotonin reuptake inhibitors (SSRIs)

Selective serotonin reuptake inhibitors (SSRIs) are one of the most commonly prescribed classes of antidepressant medications. They are widely used in mental health care to treat depression, anxiety disorders, and several related conditions. SSRI drugs are often chosen as a first treatment because they are generally effective, well-studied in clinical trials, and easier to tolerate than older antidepressants. By helping balance certain neurotransmitters in the brain, SSRIs can improve mood, emotional stability, and daily functioning for many people.

SSRIs are a type of antidepressant that affects how brain cells communicate with each other. They are used to treat numerous conditions and may be used in many settings, not just in primary care or psychiatry.

SSRIs are FDA-approved to treat major depressive disorder, anxiety disorders, obsessive-compulsive disorder, panic disorder, post-traumatic stress disorder, and other conditions. Also, some SSRIs are used for bulimia and binge eating disorder.

SSRIs work by increasing levels of serotonin, an important neurotransmitter involved in mood, sleep, appetite, and emotional regulation. Brain cells release serotonin to send signals between neurons. Normally, serotonin is reabsorbed back into the cell after it sends its message. SSRIs block this reuptake process.

By slowing serotonin reabsorption, SSRI antidepressants allow more serotonin to remain available between brain cells. Over time, this helps strengthen communication between neurons and can improve symptoms of depression and anxiety. This mechanism of action is different from monoamine oxidase inhibitors and tricyclic antidepressants, which affect multiple neurotransmitters such as norepinephrine and dopamine in broader ways.

Common SSRIs prescribed today include:

• Fluoxetine (Prozac)
• Paroxetine (Paxil)
• Sertraline (Zoloft)
• Citalopram (Celexa)
• Escitalopram (Lexapro)
• Fluvoxamine (Luvox)
• Vilazodone (Viibryd)

Each SSRI has slightly different pharmacology, dosing, and side effect profiles. Some may be more stimulating, while others may cause more drowsiness. Your healthcare provider considers symptoms, age, medical history, and potential interactions when prescribing.

SSRIs are primarily used to treat major depressive disorder, including severe depression. They are also commonly prescribed for:

• Anxiety disorders
• Panic disorder
• Obsessive-compulsive disorder (OCD)
• Post-traumatic stress disorder
• Social anxiety disorder
• Bulimia and binge eating disorder
• Premenstrual dysphoric disorder
• Off-label use for certain mood or pain conditions

SSRIs may be used alone or combined with other treatment options such as cognitive behavioral therapy. For some people, SSRIs are part of long-term antidepressant use, while others may take them for a shorter period.

Side effects of SSRIs vary depending on the medication and the individual. Common side effects include:

• Nausea and other gastrointestinal symptoms
• Dry mouth
• Drowsiness or insomnia
• Headache
• Weight gain or weight loss
• Sexual dysfunction, including reduced libido or difficulty reaching orgasm

Some people experience increased anxiety during the first few weeks of taking SSRIs.

Rare but serious side effects include:

• Serotonin syndrome: fever, confusion, rapid heart rate, and muscle stiffness
• Increased risk of bleeding
• New or worsening depression or suicidal thoughts, especially in people under 25 years of age
• Heart rhythm changes

These are not all of the possible side effects of selective serotonin reuptake inhibitors (SSRIs). You should always seek medical advice from your healthcare provider for any questions or concerns about your medical condition or treatment. Read all patient information, medication guides, or drug information sheets that come with this medication. You can also report adverse effects to the Food and Drug Administration at www.fda.gov/medwatch or 1-800-FDA-1088.

Although these medications are generally well-tolerated and safe, there are certain warnings, precautions, and drug interactions you should be aware of.

Warnings

Before starting selective serotonin reuptake inhibitors (SSRIs), it is crucial to discuss any existing health conditions with your healthcare provider. You should be sure that your healthcare provider is aware of all your medical conditions, including if you have:

• Bipolar disorder or a history of mania
• A seizure disorder
• Liver or kidney disease
• Bleeding problems
• A history of suicidal thoughts
• Use of other antidepressant medications or supplements

Stopping SSRIs suddenly can lead to discontinuation syndrome. This can cause dizziness, irritability, nausea, and flu-like symptoms. Tapering under medical supervision is recommended.

Boxed Warning

SSRIs carry a boxed warning about an increased risk of suicidal thoughts and behaviors in children, adolescents, and young adults, especially during the first few months of treatment or during dose changes. Close monitoring is recommended during this time.

Contraindications

SSRIs should not be taken with monoamine oxidase inhibitors or other MAOIs due to the risk of serotonin syndrome. A waiting period is required when switching between these medications. Some SSRIs may also be contraindicated in people with certain heart rhythm conditions.

Drug interactions

When Selective serotonin reuptake inhibitors (SSRIs) are taken with other prescription drugs, over-the-counter medications, vitamins, and supplements, it may change how they work or increase the frequency or severity of side effects. Make sure that you tell your healthcare professional about anything that you are taking to avoid any negative drug interactions, including:

• MAOIs and other monoamine oxidase inhibitors
• Serotonin and norepinephrine reuptake inhibitors (SNRIs), TCAs, and other antidepressants
• St. John’s wort
• Certain migraine medications
• Blood thinners and NSAIDs
• Some antibiotics and antifungal drugs

Always tell your healthcare provider and pharmacist about everything you are taking, as some of these interactions can be life-threatening.