33: Antidepressants Flashcards Preview

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Flashcards in 33: Antidepressants Deck (48):
1

symptoms of major depression

- depressed mood
- anhedonia (loss of pleasure) and loss of interest in life

2

gold standard treatment for major depression

electroconvulsive therapy

3

2 common reasons why chemical antidepressants may not work for people?

- delay of therapeutic response (weeks or months of regular dosing to achieve benefit)

- side effects can limit usage, especially in elderly

4

What are the two hypotheses of depression?

1. Monoamine/Biogenic Amine hypothesis (abnormalities in 5HT, NE, and DA neurotransmission

2. Neurotrophic Hypothesis (changes in nerve growth factors BDNF play a role in cell survival and synaptic plasticity)

these two hypotheses are likely not mutually exclusive

5

BDNF -->

TRK-B receptors --> increased neuronal survival and growth

antidepressants increase BDNF in the brain: neurotrophic hypothesis

6

side effects = GI disturbances, anxiety, sexual dysfunction

5HT reuptake blockade

7

side effects = tremors, tachycardia

NE reuptake blockade

8

side effects = psychomotor activation, antiparkinsonian effects, psychosis, increased attention and concentration

DA uptake blockade

9

side effects = sedation, drowsiness, weight gain, hypotension

H1 receptor blockade

10

side effects = blurred vision, dry mouth, sinus tachycardia, constipation, urinary retention, memory dysfunction

Muscarinic Ach receptor blockade

11

side effects = postural hypotension, reflex tachycardia, dizziness

a1 receptor blockade (adrenergic)

12

MOA MAOIs

increase synaptic availability of NE and 5HT blocking their catabolism via inhibition of MAO enzymes

13

MAO-A vs. MAO-B

MAO-A : targets tyramine, NE, 5HT and DA

MAO-B : targets mainly DA

14

irreversible MAO-A and MAO-B inhibitors

phenelzine
tranylcypromine

15

MOA selegiline

MAO-B inhibitor at low dose, non-selective MAOi at higher dose

16

low dose use selegline

parkinson's disease

17

antidepressant use selegline

high dose (patch to prevent first pass effect and tyramine effect)

18

tyramine and MAOIs --->

hypertensive crisis

19

tyramine and MAOIs --->

hypertensive crisis

amine from tyrosine triggers release of catecholamines in the synapse leading to overwhleming vasoconstriction and a hypertensive crisis

watch out for cheese and chianti wines especially

20

current major clinical use for TCAs

chronic pain conditions

used for major deprssion if SSRIs are not effective

21

MOA TCAs

block reuptake of both 5HT and NE by inhibition of SERT and NET respectively

dirty drugs - also work as agonists at cholinergic, histaminergic and a-adrenergic receptors

22

which TCA is used to treat enuresis (bedwetting)?

imipraimine

23

which TCA is more effective at treating neuropathic pain?

desipramine

has stronger NE than 5HT properties

24

which TCA is known for sedative effects?

amitriptyline

25

why are TCAs known as "hip breakers" in elderly patients?

antagonist action at alpha1 receptors --> orthostatic hypotension

also have dry mouth, constipation, blurred vision, urinary retention and confusion side effects due to antagonist actions at muscarinic receptors

26

most serious side effect of TCAs

lethal cardiac arrhythmias

due to Na/Ca channel blocking properties

27

3 C overdose of TCAs

convulsion
coma
cardiac arrhythmia

28

MOA SSRIs

selectively inhibit SERT and block the reuptake of 5HT into the presynaptic terminal --> increases synaptic 5HT

29

short term side effects SSRIs =
long term =

short term = nausea, GI upset, diarrhea (1st week)

long term = sexual dysfunction

30

observe: lethargy, restlessness, mental confusion, flushing, diaphoresis, tremor

Serotonin Syndrome

-rare side effect of SSRIs due to long half-life that occurs usually when drug combos or switching meds

31

which SSRIs pose the greatest risk for discontinuation syndrome?

paroxetine and sertraline

sudden discontinuation of short half-life SSRIs may cause advers side effects such as dizziness, paresthesias, and anxiety 1-7 days after stopping because of sensitization

switch to SSRI with longer half-life and then discontinue if pt is susceptible to this effect

32

MOA SNRI

selective serotonin-norepinephrine reuptake inhibitors

both inhibit serotonin SERT and norepinephrine NET transporters

unlike TCAs do not have much affinity for other receptors --> better side effect profile

33

clinical use venlafaxine

SNRI used for severe depression

34

clinical use duloxetine

SNRI with increasing use for chronic pain over TCAs

35

Trazodone is a...

5HT2 antagonist that also blocks H1 receptor --> sedative effects without tolerance or dependence

36

negative side effect of trazodone

priapism

due to peripheral a1 blocking effect

37

smoking cessation drug

bupropion

38

MOA bupropion

blocks NE and DA reuptake and increases presynaptic release of catecholamines

39

MOA mirtazapine

blocks presynpative a2 receptors and increase synaptic release of 5HT and NE
- blocks 5HT2 and 5HT2 (antiemetic)
blocks H1 receptor --> sedation, weight gain, few sexual side effects

40

major side effect SNRIs

discontinuation syndrome

41

what anti-depressants can you combine?

MAOIs, TCAs, and SSRIs should NOT be combined - fatal side effects!

42

which drugs are potent inhibitors of CYP2D6?

paroxetine
fluoxetine
fluvoxamine

43

drug of choice for bipolar disorder

lithium

mood-stabilizing. depressive phase requires use of anti-depressants

44

anticonvulsants used in bipolar disorder treatment

valproic acid and carbamazepine

45

treatment of acute mania

valproic acid and carbamazepine

46

MOA lithium

prevents recycling of inositol phosphate (mood dampening) and inhibits release of NE (prevent mania)

47

4 side effects of lithium

-tremor
- hypothyroidism
-nephrogenic diabetes insipidus
- skin rxn

48

what drugs interact with lithium?

thiazide and loop diuretics --> diminish Li clearance and can cause toxicity