Antidepressants

Question 1

Therapeutic Use of MAOIs

Answer 1

Atypical depression (spending a lot of time in bed, eating a lot, etc)
Treatment-resistant depression
Treatment-resistant panic disorder
Treatment-resistant social anxiety disorder

Question 2

Two MAOIs that I need to know

Answer 2

Phenelzine
Tranylcypromine
Inhibit both MAOA and MAOB

Question 3

MAOI mechanism of action

Answer 3

Inhibit the degradation of biogenic amines in the presynaptic terminals. get an increase in serotonin, NE, DA.

Question 4

What type of inhibitor are MAOIs?

Answer 4

Irreversible inhibitor, so it takes at least 2 weeks for enzymes levels to recover

Question 5

MAOI side effects

Answer 5

Serotonin syndrome (if combined with other serotonergic drugs)
Hypertension/hypertensive crisis (when given adrenergics (decongestants) or stimulants) also caused by tyramine, weight gain, insomnia

Question 6

Serotonin syndrome

Answer 6

Autonomic effects (sweating, tremor, tachycardia)
Mood effects (agitation)
Motor effects (myoclonus, hyperreflexia)

Question 7

Drugs that, when combined with MAOIs, can lead to serotonin syndrome

Answer 7

SSRIs, carbamazepine, meperidine, fentanyl, methadone, tramadol

Question 8

Tyramine induced hypertensive crisis

Answer 8

Can be triggered by the ingestion of tyramine rich foods like cheese, red wine, soy, beer. Tyramine is a catecholamine releasing agent that is broken down by MAOa in gut, if it gets access to sympathetic neurons and will cause release of NE, causing increased BP.

Question 9

When can somebody who was on MAOIs eat tyramine again?

Answer 9

Two weeks after to allow the enzyme to regenerate.

Question 10

Selegiline transdermal

Answer 10

MAOI that is higher dose so it inhibits both MAOA and MAOB.

Question 11

Why is selegiline better when given transdermally

Answer 11

Bypass GI and liver so patients can eat tyramine without having a hypertensive crisis.

Question 12

Tertiary Amine Tricyclic Antidepressant

Answer 12

Amitriptyline (also used in migraine prevention)

Question 13

Secondary Amine Tricyclic Antidepressants

Answer 13

Nortriptyline and Desipramine

Question 14

Therapeutic uses for TCAs

Answer 14

Depression and treatment resistant depression, childhood bedwetting, GAD, Panic disorder, obsessive compulsive disorder, neuropathic pain, fibromyalgia

Question 15

How do TCAs work?

Answer 15

The inhibit the reuptake of NE. Tertiary amines (like amitriptyline) inhibit some 5HT reuptake as well.

Question 16

Side effects of TCAs?

Answer 16

Very dirty drugs:
H1 blockade (weight gain, sedation)
Na channel blockade (anti arrhythmic effects, but can lengthen QT intervals)
M1 blockade (blurry vision, constipation, dry mouth)
Overdose can cause heart block.

Question 17

When to avoid TCAs?

Answer 17

In patients with narrow angle glaucoma, recent cardiac events, prolonged QT. Secondary amines preferable in elderly.

Question 18

Are TCAs lethal in overdose?

Answer 18

Yes, absolutely. Cause heart block.

Question 19

Anticholinergic toxicity

Answer 19

Red as a beet, dry as a bone, blind as a bat, mad as a hatter, hot as a hare, full as a flask.

Question 20

What happens to tertiary amines when they are broken down by CYPs?

Answer 20

Broken down into secondary amines.

Question 21

Can TCAs be given with MAOIs?

Answer 21

No way jose. That would be terrible. Cause serotonin syndrome. Wait 14 days for MAOIs to wash out.

Question 22

Dosing of TCAs?

Answer 22

Narrow therapeutic index, start low and titrate slowly.

Question 23

SSRI therapeutic uses

Answer 23

MDD
GAD
Panic Disorder
PTSD
OCD
PMDD
Bulimia

Question 24

Common side effects with SSRIs

Answer 24

GI upset, weight gain, loss of sex drive, headache, akathisia

Question 25

Metabolism of SSRIs

Answer 25

Significant first pass metabolism. Metabolized in liver by CYPs

Question 26

SSRIs with most drug interactions

Answer 26

Fluvoxamine and fluoxetine

Question 27

SSRIs with the least drug interactions

Answer 27

Citalopram and escitalopram

Question 28

SSRI with the longest half life and least withdrawal?

Answer 28

Fluoxetine

Question 29

SSRI with the shortest half-life and most withdrawal?

Answer 29

Paroxetine

Question 30

Most selective SSRI

Answer 30

Escitalopram

Question 31

When does SSRI withdrawal occur and what are the symptoms?

Answer 31

Occurs as a result of abrupt discontinuation of SSRI after at least 6 weeks of treatment. Feels like the flu. Usually resolves in 3 weeks.

Question 32

Why are SSRIs preferred over other agents?

Answer 32

No cardiac symptoms, simple dosing, typically not lethal. No special diet.

Question 33

SNRIs include

Answer 33

Venlafaxine, duloxetine

Question 34

SNRI therapeutic uses. Common problem?

Answer 34

MDD
GAD
Neuropathic pain
Fibromyalgia

May increase BP.

Question 35

Venlafaxine mechanism and side effects.

Answer 35

At high doses, acts like an SNRI. Low doses, like an SSRI. High doses can cause increase diastolic BP and can cause tachycardia

Question 36

Duloxetine

Answer 36

SNRI, for MDD GAD.

Question 37

Buproprion

Answer 37

Wellbutrin– Used for MDD and smoking cessation, also can be used for ADHD. Weak NE and DA repute inhibitor, inhibitor of nAChRs. No sexual dysfunction/weight gain.

Question 38

Buproprion adverse effect?

Answer 38

May cause seizures. Avoid in patients with eating disorders (who may have electrolyte balances)

Question 39

Mirtazapine

Answer 39

Noradrenergic and Specific Serotonergic antidepressant. Antagonizes a2 receptors (enhancing adrenergic transmission because of the auto receptor), indirect agonist of 5HT1 because it blocks 5HT2A and 5HT3, so remaining serotonin shunted to 5HT1A. Weight gain mediated by H1 antagonism, also increased somnolence.

Question 40

Trazodone

Answer 40

5HT2A receptor antagonist, mild SNRI, used as sleep aid. Orthostatic hypertension and priapism.

Question 41

Why prescribe a SNRI?

Answer 41

If depression with a comorbid pain disorder.