Antidepressants | TCAs

Question 1

What are the medications found in this class?

Answer 1

A. Third Generation (non-selective):
1. Amitriptyline
2. Imipramine
3. Clomipramine
B. Second Generation (selective):
1. Nortriptyline
2. Desipramine

Question 2

What is their mechanism of action?

Answer 2

They work by inhibiting the reuptake of serotonin and norepinephrine (third generation, non-selective) or norepinephrine alone (second generation, selective) leading to an increase in the levels of those neurotransmitters alleviating the effects of major depressive disorder.

Question 3

What are their indications?

Answer 3

1. Major Depressive Disorder (last resort, due to many side effects)
2. Chronic Neuropathic Pain
3. Phobic Disorders.

Drug-Specific Indications include:
1. Clomipramine: OCD
2. Imipramine: Nocturnal Enuresis

Question 4

What are their side effects?

Answer 4

1. Anti-Histamine: sedation
2. Anti-Muscaranic: Atropine like effects (most common with third generation medications)
3. Anti-adrenergic: Orthostatic Hypotension
4. Serotonin Syndrome
5. Cardiotoxicity: can lead to arrhythmias (corrected by giving sodium bicarbonate)
6. If given with ethanol or a sedative medication it can lead to respiratory failure and death.