Medicine & USMLE


Alpha & Beta Blockers (New)
  1. Phentolamine
  2. Phenoxybenzamine
  3. -osin Drugs
  4. Beta-1 Selective Beta Blockers
  5. Dual Alpha Beta Blockers
  6. Mirtazapine


Mirtazapine is an atypical antidepressant drug.

It works as an selective alpha-2 antagonist, which increases the release of norepinephrine and serotonin. Mirtazapine also blocks 2 subtypes of serotonin receptors: 5HT-2 and 5HT-3. Additionally, mirtazapine is a H1 receptor antagonist.

Side effects of mirtazapine include weight gain, increased appetite, hyperlipidemia, sedation, and dry mouth.

Key Points

  • Mirtazapine
    • Mechanism
      • Blocks Alpha-2 Receptors
        • Increases release of norepinephrine (NE)
        • Increases release of serotonin (5-HT)  
      • Blocks 5HT2 and 5HT3 Serotonin Receptors
      • Blocks H1 Receptors
    • Clinical Use
      • Treats Depression
        • Atypical antidepressant
    • Side Effects
      • Increased appetite
        • Causes weight gain
        • Used in underweight patients or those with anorexia nervosa
      • Causes Sedation
        • Used in patients with insomnia
      • Increases Serum Cholesterol
      • Causes Dry Mouth