PHARM | SSRIs-Fluoxetine
Description
π HIGH-YIELD SSRI OVERVIEW (80/20 Rule) (Selective Serotonin Reuptake Inhibitors)
π§ Core Concept: SSRIs β serotonin levels by blocking reuptake in the synaptic cleft β boosting mood, reducing anxiety, and stabilizing emotional regulation.
π Top Drugs to Know: Fluoxetine (Prozac) π Sertraline (Zoloft) π Escitalopram (Lexapro) π Citalopram (Celexa) π€ Paroxetine (Paxil) β οΈ (sedating, more withdrawal risk)
π©Ί Main Indications (What Youβll Actually See):
- Depression (MDD)
- Anxiety Disorders (GAD, panic, OCD, PTSD, social anxiety)
- PMDD & Bulimia (Fluoxetine)
- Panic Disorder (Sertraline)
β‘οΈ Mechanism of Action (Simple): Blocks serotonin reuptake pump β serotonin stays longer in the synapse β improved mood & less anxiety.
β± Onset: Takes 2β4 weeks for full effect. Educate patients early: βYou wonβt feel better overnight.β
β οΈ Major Side Effects (Know These Cold):
- Sexual dysfunction (β libido, anorgasmia)
- GI upset (nausea, diarrhea early on)
- Insomnia or sedation (drug-dependent)
- Weight changes (gain with Paroxetine)
- Headache
- Serotonin Syndrome π β mental status changes, hyperreflexia, myoclonus, fever, shivering (esp. with MAOIs, St. Johnβs Wort, or triptans). π Tx: Stop SSRI, give benzodiazepines, supportive care, Β± cyproheptadine.
π£ Black Box Warning: β suicidal thoughts in adolescents & young adults (esp. in first few weeks).
π« Contraindications & Cautions:
- MAOIs β must wait 14 days between use β risk of serotonin syndrome.
- Avoid abrupt discontinuation β causes flu-like withdrawal (esp. Paroxetine).
π 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).
π§© 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.
π§ 80/20 Takeaway: SSRIs = first-line for depression/anxiety. Know onset delay, serotonin syndrome signs, sexual dysfunction, and black box warning.
β³ 2β4 weeks to work. Watch early mood shifts. Donβt mix with MAOIs.
β¨ Start low, go slow, and monitor the glow (serotonin).






