• Using your textbooks, draw up a classification of the drugs that are used as antidepressants.
  • • • • Tricyclic antidepressants
        • Monoamine oxidase inhibitors
        • Serotonin Noradrenaline Re-uptake Inhibitors
        • Serotonin receptor modulators
        • Noradrenaline Receptor Inhibitors
        • Tetracyclic and unicyclic antidepressants
        • Circadian rhythm regulators
        • Selective Serotonin Re-uptake Inhibitors.

• What do the existing drugs all have in common regarding their mechanisms of action?

They all influence serotonin and noradrenaline levels.

• How long does it take for the antidepressive effects of these drugs to appear? What is the reason for this?

3-5 weeks. It takes a while to establish a new homeostasis.

• How do the TADs and the selective serotonin reuptake inhibitors (SSRI’s) differ in respect of:
  • • Efficacy: individuals have different responses, but the efficacy is the same for both.
    • Side effects: TAD has anti-cholinergic, alpha-lytic and quinidine-like effects. SSRI’s have insomnia, non-sedating, GIT disturbances.
    • Safety: SSRI’s are safe and have fewer side effects than TAD. SSRI’s may cause serotonin syndrome.

• What is the action of mirtazapine?

It blocks alpha1, alpha2, H1, 5-HT2a and 5-HT3 receptors. It also indirectly stimulates 5-HT1a receptors.

• What is the action of venlafaxine?

It blocks both serotonin and noradrenaline re-uptake. It also moderately blocks SERT and NET.

• What is the action of agomelatine?

It is an antagonist on the 5-HT2c receptors and an agonist on the melatonergic receptors (MT1 and MT2). It adjusts melatonin levels.