PHARM | SSRIs-Fluoxetine

💊 HIGH-YIELD SSRI OVERVIEW (80/20 Rule) (Selective Serotonin Reuptake Inhibitors)

🧠 Core Concept: SSRIs ↑ serotonin levels by blocking reuptake in the synaptic cleft — boosting mood, reducing anxiety, and stabilizing emotional regulation.

📋 Top Drugs to Know: Fluoxetine (Prozac) 🌀 Sertraline (Zoloft) 🌊 Escitalopram (Lexapro) 💎 Citalopram (Celexa) 🌤 Paroxetine (Paxil) ⚠️ (sedating, more withdrawal risk)

🩺 Main Indications (What You’ll Actually See):

• Depression (MDD)
• Anxiety Disorders (GAD, panic, OCD, PTSD, social anxiety)
• PMDD & Bulimia (Fluoxetine)
• Panic Disorder (Sertraline)

⚡️ Mechanism of Action (Simple): Blocks serotonin reuptake pump → serotonin stays longer in the synapse → improved mood & less anxiety.

⏱ Onset: Takes 2–4 weeks for full effect. Educate patients early: “You won’t feel better overnight.”

⚠️ Major Side Effects (Know These Cold):

• Sexual dysfunction (↓ libido, anorgasmia)
• GI upset (nausea, diarrhea early on)
• Insomnia or sedation (drug-dependent)
• Weight changes (gain with Paroxetine)
• Headache
• Serotonin Syndrome 💀 → mental status changes, hyperreflexia, myoclonus, fever, shivering (esp. with MAOIs, St. John’s Wort, or triptans). 👉 Tx: Stop SSRI, give benzodiazepines, supportive care, ± cyproheptadine.

💣 Black Box Warning: ↑ suicidal thoughts in adolescents & young adults (esp. in first few weeks).

🚫 Contraindications & Cautions:

• MAOIs — must wait 14 days between use → risk of serotonin syndrome.
• Avoid abrupt discontinuation — causes flu-like withdrawal (esp. Paroxetine).

💉 Nursing Implications:

• Monitor mood, anxiety, suicidal ideation early in therapy.
• Educate on delayed effect & adherence.
• Watch for serotonin syndrome if combined with other serotonergic agents.
• Encourage taking same time daily.
• Sertraline often best for patients with cardiac disease (safe profile).

🧩 Clinical Pearls:

• Fluoxetine = longest half-life (good for poor adherence).
• Paroxetine = most sedating, highest withdrawal risk.
• Sertraline = go-to for anxiety & PTSD.
• Escitalopram = cleanest side effect profile.

🧠 80/20 Takeaway: SSRIs = first-line for depression/anxiety. Know onset delay, serotonin syndrome signs, sexual dysfunction, and black box warning.

⏳ 2–4 weeks to work. Watch early mood shifts. Don’t mix with MAOIs.

✨ Start low, go slow, and monitor the glow (serotonin).