Pharmacology of Antidepressants and Mood Stabilisers

Question 1

which drugs diffuse most effectively across the blood brain barrier

Answer 1

hydrophobic/lipophilic

need to diffuse through the fatty barrier

Question 2

what do psychiatric drugs need to pass through to be effective

Answer 2

blood brain barrier

Question 3

clinical uses of antidepressants

Answer 3

Moderate to severe depression 
Dysthymia 
Generalised anxiety disorder 
Panic disorder, OCT, PTSD
Premenstrual dysphoric disorder 
Bulimia nervosa 
Neuropathic pain

Question 4

what are the types of antidepressants

Answer 4

Monoamine oxidase inhibitors

Monoamine reuptake inhibitors

• tricyclics
• SSRI (selective serotonin reuptake inhibitor)
• noradrenaline reuptake inhibitor

Question 5

what are monoamines

Answer 5

dopamine
noradrenaline
seratonin (5HT)

(serotonin and noradrenaline are the ones antidepressants effect most)

Question 6

what is the monoamine hypothesis

Answer 6

depression results from a functional defect of monoamine transmitters
(especially serotonin and noradrenaline)

drugs which deplete monoamine stores cause low mood

Question 7

where does serotonin originate/travel

Answer 7

rostral area of the midbrain - then projects around the cortex

Question 8

what does serotonin (5HT) impact

Answer 8

mood 
sleep 
feeding 
behaviour 
sensory perception

Question 9

what is the base monoamine (where they originate from)

Answer 9

tryptophan

Question 10

how is serotonin produced

Answer 10

tryptophan 
-converted by tryptophan hydroxyls 
to 5 OH Tryptophan 
-L-AA decarboxylase converts it to 
5HT

Question 11

what does noradrenaline impact

Answer 11

arousal

emotion

Question 12

how ado monoamine oxidase inhibitors work (MAO inhibitor)

Answer 12

inhibit monoamine oxidase enzyme which breaks down neurotransmitter into metabolites

Question 13

examples of MAO inhibitors

Answer 13

Phenelzine

Moclobemide

Question 14

which MAO inhibitor is reversible

Answer 14

moclobemide

Question 15

which MAO inhibitor is irreversible

Answer 15

Phenelzine

Question 16

side effects of monoamine oxidase inhibitors

Answer 16

• ‘Cheese reaction’ - hypertensive crisis (caused by inhibition of monoamine oxidase enzyme in gut preventing breakdown od dietary tyramine)
• potentiates effects of other drugs by decreasing their metabolism
• insomnia
• postural hypotension
• peripheral oedema

Question 17

what kind of symptoms are caused by tricyclics

Answer 17

anticholingeric side effects

Question 18

what kind of anti depression would you NOT give to someone with an ischaemic heart disease history

Answer 18

Tricyclics - they are cardiotoxic

Question 19

what kind of anti depression would you NOT give to someone with an ischaemic heart disease history

Answer 19

Tricyclics - they are cardiotoxic - cause tachycardia, arrhythmia, postural hypotension

Question 20

what are some examples of tricyclics

Answer 20

Impiramine
Dosulepin
Amitriptyline
Lofepramine

Question 21

how do tricyclics work

Answer 21

block noradrenaline transporter taking noradrenaline back to the presynaptic neurone to be reuptaken so it stays in the synapse

Question 22

how do SSRIs work

Answer 22

blocks serotonin transporter taking serotonin back to the presynaptic neurone to be reuptaken so it stays in the synapse

Question 23

examples of SSRIs

Answer 23

Fluoxetine
Citalopram/escitalopram
Setraline
Paroxetine

Question 24

Side effects of SSRIs

Answer 24

nausea 
headache 
sweating/vivid dreams 
worsened anxiety 
sexual dysfunction 
hyponatraemia (in elderly) 
transient increase in self-harm/suicidal ideation in young people
effects come back when you stop them too

Question 25

what are other monoamine reuptake inhibitors

Answer 25

SNRIs | venlafaxine, duloxetine

Question 26

how do SNRIs and dual reuptake inhibitors work

Answer 26

block reuptake of monoamines into presynaptic terminals similar side effects to SSRIs lack major receptor blocker actions so more limited range of side effects than tricyclics

Question 27

what is mirtazapine

Answer 27

atypical antidepressant - blocks post-synaptic serotonin receptors - blocks seretenergic side effects if given with SSRIs

Question 28

side effects or mirtazapine

Answer 28

weight gain + sedation

Question 29

what is the most effective antidepressant

Answer 29

isn't one - all similar clinical efficiency depends what causes the least side effects in different people only effective in moderate-severe depression

Question 30

whats the aims of bipolar disorder treatments

Answer 30

Reduce mood in mania Raise mood in depression long term - stabilise mood and prevent recurrence of mania and depression

Question 31

what side effects suggests lithium levels are in a toxic range

Answer 31

ataxia

Question 32

how is lithium metabolised

Answer 32

it isn't bc its an element and elements are not metabolism excreted in urine as lithium

Question 33

what happens to lithium levels in dehydration

Answer 33

they are increased (Na and lithium are indistinguishable to renal tubules)

Question 34

how does lithium work

Answer 34

mood stabiliser blocks phosphatidylinostitol pathways or inhibits glycogen synthesis

Question 35

side effects of lithium

Answer 35

``` dry mouth/strange taste polydipsia & polyuria tremor hypothyroidism long term reduced renal function nephrogenic diabetes insidious weight gain ```

Question 36

toxic effects of lithium

Answer 36

``` vomiting diarrhoea ataxia/coarse tremor drowsiness convulsions coma ```

Question 37

which mood stabiliser do you do NOT give to women trying to get pregnant

Answer 37

Valporic acid (an anticonvulsant as a mood stabiliser) - mode of action unclear- may block overactive pathways

Question 38

side effects of anticonvulsants

Answer 38

valproate & carbamazepine - - drowsiness, ataxia, cardiovascular effects, induced liver enzymes valporate- teratogenicity lamotrigine - very small risk of Stevens Johnson syndrome