Medicine & USMLE


Mental Health Drugs
  1. Tricyclic Antidepressants
  2. SSRIs
  3. SNRIs
  4. Benzodiazepines
  5. Barbiturates
  6. Typical Antipsychotics
  7. Atypical Antipsychotics
  8. Extrapyramidal Symptoms
  9. Lithium
  10. MAOIs
  11. Bupropion
  12. Buspirone
  13. Trazodone
  14. Zolpidem
  15. Amphetamines
  16. Mirtazapine


Serotonin-selective reuptake inhibitors, abbreviated as SSRIs, are antidepressant drugs used to treat both depression and anxiety. Drug names of the SSRIs to know include citalopram, escitalopram, sertraline, paroxetine, and fluoxetine. Common side effects include sexual dysfunction and weight gain. Another important adverse effect is serotonin syndrome, which is a medical emergency resulting from an overload of serotonin in the body, manifesting as hypertension, tachycardia, muscle rigidity, and diarrhea. The risk for Serotonin syndrome can be reduced by teaching the patient to avoid other serotonin-altering substances like MAOIs, St. John’s Wort, as well as avoiding any and all grapefruit products.

Key Points

  • Key drugs
    • Citalopram
    • Sertraline
    • Paroxetine
    • Fluoxetine
    • Escitalopram
    • Fluvoxamine
    • Mechanism
      • Antidepressant
        • Increases serotonin in the CNS by blocking its reuptake at the neuron ends
        • Therapeutic effects may take up to 4 weeks
    • Clinical Use
      • Depressive Disorders
        • Increased serotonin is thought to improve mood states
        • First-line treatment
          • Generally preferred over other antidepressants (MAOIs, TCAs, etc.) because of fewer side effects
      • Anxiety Disorders
        • Generalized anxiety disorder
        • Post-traumatic stress disorder (PTSD)
        • Phobias
        • Panic disorders
        • Obsessive-Compulsive Disorder (OCD)
          • Low serotonin levels is thought to play a role in OCD
    • Side Effects and Adverse Reactions
      • Increased risk of side effects with (avoid!)
        • MAOIs
          • Discontinue 14 days before starting an SSRI and vice versa
        • St John’s Wort
        • Grapefruit
      • Serotonin Syndrome (think overactive everything)
        • Hyperthermia, Sweating
        • Tachycardia, hypertension
        • Muscle rigidity, loss of muscle coordination
        • Dilated pupils
        • Diarrhea
        • Agitation or restlessness
        • Confusion
        • Headache
        • Shivering
        • Goosebumps
        • If patient experiences serotonin syndrome symptoms, the SSRI should be stopped and provider notified
      • Increased risk of suicidal thoughts or behavior
        • Priority!
        • Seen at the beginning of therapy but should diminish over time
        • The patient will receive an increase in energy before they experience an increase in mood. Patients, especially young adults, need to be monitored for increased suicidal ideation, as they may now have the energy to follow through with the suicide plan
      • Sexual Dysfunction
        • Common side effect, experienced in over 50% of patients
        • If patient is still experiencing sexual dysfunction after 2-4 weeks of treatment initiation, they should be encouraged to report this to the provider for a possible change in medication
        • Noncompliance is common with SSRIs due to side effects of sexual dysfunction and weight gain.
      • Weight gain
        • Common side effect of taking SSRIs
        • A healthy diet and regular exercise should be encouraged to combat weight gain
      • Other drug interactions
        • Use caution with concurrent use of digoxin, warfarin, diazepam, NSAIDS, aspirin, alcohol, and other CNS depressants
      • GI Distress
        • Nausea, vomiting, diarrhea, anorexia
      • Insomnia