Antidepressants

Question 1

How do MAOIs work?

Answer 1

Irreversible inhibitors of MAO in presynaptic neurons which leads to increase in 5-HT (serotonin), dopamine, and norepi

Question 2

What is the major side effect of MAOIs?

Answer 2

Tyramine-induced hypertensive crisis
Dietary causes - cheese, fava beans, liver, soy sauce, sauerkraut, fermented foods, cured meats
Medical causes - cold meds, pain killers

Question 3

How does tyramine induced hypertensive crisis work?

Answer 3

MAO breaks down tyramine in gut
When it’s not broken down, it has adrenergic properties
Sudden catastrophic rise in BP

Question 4

What are the contraindications to MAOIs? What can it lead to?

Answer 4

Co-administration with any other antidepressant except for TCAs
Serotonin syndrome

Question 5

What are the 4 MAOIs?

Answer 5

Phenelzine (Nardil)
Tranylcypromine (Parnate)
Isocarboxazid (Marplan)
Selegeline (Emsam)

Question 6

What are the minor side effects of MAOIs

Answer 6

Most common = adrenergic - orthostatic hypotension
Second most common = insomnia
weight gain
sexual dysfunction
mania

Question 7

How do TCAs work?

Answer 7

Antagonist at presynaptic 5-HT and NE reuptake pumps

Increases serotonin and NE in the synapse

Question 8

How long do TCAs take to work?

Answer 8

3-4 weeks after initiation

Question 9

What are the tertiary amine TCA drugs?

Answer 9

Amitriptyline (Elavil)
Clomipramine (Anafranil)
Doxepin (Sinequan)
Trimipramine (Surmontil)
Imipramine (Tofranil)

Question 10

What are the side effects of tertiary amine TCAs?

Answer 10

More anticholinergic, histaminergic, and adrenergic side effects
More dangerous in overdose

Question 11

What are the secondary amine TCA drugs?

Answer 11

Desipramine (Norpramin)
Nortriptyline (Pamelor)
Protriptyline (Vivactil)

Question 12

What are the side effects of secondary amine TCAs?

Answer 12

Less anticholinergic/histaminergic/adrenergic = less sedation and less orthostatic hypotension than tertiary

Question 13

What are the characteristics of TCAs?

Answer 13

Highly protein bound - will interact with other protein bound drugs
Highly anticholinergic
Causes QTc prolongation
Sexual dysfunction

Question 14

What are contraindications to TCAs?

Answer 14

Cardiac conduction delays
Arrhythmias
BPH - causes urinary retention and post void residual, leading to UTIs

Question 15

What are the serious side effects of TCAs?

Answer 15

Lethal in overdose
Cardiotoxic = widened QRS, prolonged QTc, AV block, torsades
Neurotoxic = tremor, ataxia, delirium, coma, seizures

Question 16

What are the 3 C’s of TCA overdose?

Answer 16

Convulsions
Coma
Cardiotoxicity

Question 17

Treatment for TCA overdose?

Answer 17

Sodium Bicarb, Mg

Question 18

How do SSRIs work?

Answer 18

Antagonist at presynaptic 5-HT reuptake pump

Question 19

How long do SSRIs take to work?

Answer 19

3-4 weeks after initiation

Question 20

What if you want to switch from MAOI to SSRI?

Answer 20

2 week washout in between

Question 21

What are the contraindications of SSRIs?

Answer 21

Concurrent use with MAOIs –> serotonin syndrome

Question 22

What are the signs of serotonin syndrome? What is the treatment of serotonin syndrome?

Answer 22

Hyperthermia
Myoclonus
Autonomic instability
Rigidity
Coma
Death

Treatment = cyproheptatine = serotonin receptor antagonist

Question 23

What are minor side effects of SSRIs?

Answer 23

5-HT3 = GI, N/V/D
5-HT2C = anxiety and agitation
5-HT2A = anxiety, agitation, akathisia, insomnia, sexual dysfunction
Serotonin discontinuation = headache, dizziness, irritability, fatigue
weight gain
mania
Rare hyponatremia

Question 24

What is the mechanism of SNRIs?

Answer 24

Antagonism at presynaptic 5-HT and NE reuptake

At higher doses, also inhibits DA reuptake

Question 25

How do SNRIs and TCAs differ?

Answer 25

SNRIs have no anticholinergic, antihistaminergic, and antiadrenergic effects

Question 26

What are the side effects of SNRIs

Answer 26

Increased NE = tachycardia, hypertension, agitation, anxiety, akathisia, tremor, myoclonus Increased serotonin = GI symptoms, sexual dysfunction Insomnia Rare seizures Contradication = concurrent MAOI for serotonin syndrome

Question 27

What are are the SSRI drugs?

Answer 27

``` Fluoxetine (Prozac/Sarafem) Paroxetine (Paxil) Sertraline (Zoloft) Fluvoxamine (Luvox) Citalopram (Celexa) Escitalopram (Lexapro) ```

Question 28

What are the SNRI drugs?

Answer 28

Venlafexine (Effexor) Duloxetine (Cymbalta) Desvenlafexine (Pristiq)

Question 29

How do NaSSAs work?

Answer 29

Noradrenergic and Specific Serotonergic Antidepressant Antagonist at alpha2 adrenergic receptors = disinhibits NE and 5HT release Agonist at alpha 1 = increases 5HT release

Question 30

How do SARIs work?

Answer 30

Serotonin Antagnoists and reuptake inhibitors Antagonist at presynaptic 5HT reuptake pump Antagonist at post-synaptic 5-HT2A receptors = no sexual side effects!

Question 31

How do NDRIs work?

Answer 31

Antagonist at presynaptic NE and DA reuptake pumps