Mirtazapine

• Mirtazapine is a type of tetracyclic antidepressant
• MOA:

  • Presynaptic alpha2-adrenoreceptor antagonist
  • Increases central noradrenergic and serotonergic neurotransmission
• Indications:

  • Treatment of major depressive disorders following unsuccessful treatment with SSRIs
  • Mirtazapine is particularly useful in improving sleep in depressed patients with insomnia and can also increase appetite - useful for elderly frail patients
• Cautions:

  • Cardiac disorders
  • Diabetes
  • History of mania
  • History of seizures
  • History of urinary retention
  • Susceptibility to angle-closure glaucoma
• Interactions:

  • Bleeding risk - NSAIDs, anticoagulants, antiplatelets, SSRIs
  • MAOIs - risk of CNS toxicity/serotonin syndrome
• Side effects similar to SSRIs/SNRIs but higher risk of weight gain and drowsiness