Antidepressants

Question 1

What is the mechanism of action of sertraline?

Answer 1

1. SERT inhibition (block the reuptake of serotonin)
2. Mild dopamine reuptake inhibition

Question 2

What is the mechanism of action of fluoxetine?

Answer 2

1. SERT inhibition (block the reuptake of serotonin)

Question 3

What is the mechanism of action of paroxetine?

Answer 3

1. SERT inhibition (block the reuptake of serotonin)
2. Mild anticholinergic activity (by blocking ACh, anticholinergics reduce the activity of the parasympathetic nervous)

Question 4

What is the mechanism of action of citalopram?

Answer 4

1. Selective SERT inhibition (block the reuptake of serotonin)

Question 5

What is the mechanism of action of ecitalopram?

Answer 5

S-enantiomer of citalopram; more selective SERT inhibitor

Question 6

What is the mechanism of action of fluvoxamine?

Answer 6

1. SERT inhibition
   …
   (also used in OCD)

Question 7

What is the mechanism of action of venlaflaxine?

Answer 7

1. Dose-dependent SERT inhibition (low dose)
2. NET inhibition (high dose)
   …
   (serotonin transporter = SERT; norepinephrine transporter NET)

Question 8

What is the mechanism of action of desvenlafaxine?

Answer 8

Active metabolite of venlafaxine;
SERT and NET inhibition

Question 9

What is the mechanism of action of duloxetine?

Answer 9

Balanced SERT and NET inhibition
…
(also used in neuropathic pain)

Question 10

What is the mechanism of action of levomilnacipran?

Answer 10

More selective for NET More selective inhibition than SERT inhibition

Question 11

What is the mechanism of action of reboxetine?

Answer 11

Noradrenaline reuptake inhibitor (NaRI)

Question 12

What is the mechanism of action of amitriptyline?

Answer 12

1. Potent SERT inhibition
2. Potent NET inhibition
3. Strong anticholinergic and sedative
   …
   (anticholinergic drugs block the parasympathetic nervous system however sedation in this drug still predominates)

Question 13

What is the mechanism of action of nortriptyline?

Answer 13

Active metabolite of amitriptyline; less sedating:
1. Potent SERT inhibition
2. Potent NET inhibition

Question 14

What is the mechanism of action of imipramine

Answer 14

1. SERT > NET inhibition
   …
   (used for enuresis)

Question 15

What is the mechanism of action of chomipramine?

Answer 15

1. Strong SERT inhibitor
   …
   (used in OCD)

Question 16

What is the mechanism of action of doxepin?

Answer 16

1. Potent antihistamine (sedative)
2. Moderate SERT/NET inhibition

Question 17

What is the mechanism of action of trimipramine?

Answer 17

Weak monoamine reuptake inhibition
…
(sedating)

Question 18

What is the mechanism of action of mirtazapine?

Answer 18

1. Seratonin antagonist: 5HT2A 5HT2C, 5HT3
2. H1 antagonist (sedating)
3. α2 antagonist (↑NE and 5-HT)

Question 19

What is the mechanism of action of bupropion?

Answer 19

1. Norepinephrine-dopamine reuptake inhibitor (NDRI)
2. Nicotinic acetylcholine receptor antagonist

Question 20

What is the mechanism of action of trazodone?

Answer 20

Class: Serotonin Antagonist and Reuptake Inhibitor (SARI)
…
Mechanism:
1. Blocks SERT/ seratonin antagonist at 5HT1A → ↑ serotonin levels (antidepressant effect)
2. Blocks SERT/ seratonin antagonist at 5HT2A and 5HT2C (thought to cause the side effects e.g. insomnia, sexual dysfunction, anxiety)
3. H1 blocker (used for insomnia)

Question 21

What is the mechanism of action of vortioxetine?

Answer 21

1. SERT inhibitor
2. Modulates multiple 5-HT receptors
   …
   (newer agent)

Question 22

What is the mechanism of action of St John’s Wort

Answer 22

1. Weak MAOI
2. Weak SNRI
   (also considered by some to be a weak SSRI)

Question 23

What is the mechanism of action of moclobemide?

Answer 23

Reversible inhibitor of monoamine oxidase type A

Question 24

What is the mechanism of action of agomelatine?

Answer 24

1. Melatonergic agonist: MT1 and MT2
2. Seratonin antagonist: 5-HT2C