SSRIs (Selective Serotonin Reuptake Inhibitors)

Definition

SSRIs are the most commonly prescribed antidepressant class. They selectively inhibit the reuptake of serotonin in the central nervous system, increasing its availability. They are first-line for depression, anxiety disorders, OCD, PTSD, and premenstrual dysphoric disorder.

Common Drugs

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

Side Effects

• Initial: nausea, headache, insomnia (often resolve in 2 weeks)
• Sexual dysfunction (common, persistent)
• Weight changes
• GI upset
• Hyponatremia (especially elderly)
• Increased suicidal ideation (black box warning, young adults)

Serotonin Syndrome (Emergency)

Life-threatening overstimulation caused by combining serotonergic drugs (SSRI + MAOI, tramadol, triptans, St. John's wort). Signs: altered mental status, autonomic instability (hyperthermia, tachycardia, diaphoresis, mydriasis), neuromuscular hyperactivity (tremor, clonus, hyperreflexia). Treatment: stop offending agent, supportive care, benzodiazepines, cyproheptadine.

Nursing Considerations

• Therapeutic effect takes 4 to 6 weeks.
• Monitor for suicidal ideation, especially first 2 to 4 weeks.
• Do NOT combine with MAOIs. Wait 2 to 5 weeks washout period.
• Avoid abrupt discontinuation (discontinuation syndrome).
• Teach about side effect timeline and adherence.

NCLEX Relevance

Serotonin syndrome recognition and the 4 to 6 week timeline are top test points.