Antidepressants

Question 1

what SSRI has higher risk of discontinuation syndrome ?

Answer 1

paroxetine

Question 2

what SSRI is associated with QT prolongation ?

Answer 2

citalopram and escitalopram (SSRI)

Question 3

what are side effects of SSRI’s ?

Answer 3

GI
increased risk of GI bleed
risk of suicidal thoughts
anxiety and agitation
drug interactions (fluoxetine and paroxetine)
QT prolongation (citalopram and escitalopram)

Question 4

at what dose should you give citalopram and escitalopram to reduce risk of QT prolongation ?

Answer 4

risk is dose dependant

40mg in adults
20mg in > 65yrs
20mg in patients with hepatic impairment

Question 5

are SSRI’s contraindicated in pregnancy and if so what are the risks ?

Answer 5

not contraindicated but risk vs benefits should be discussed

if taken in 1st trimester - cardiac abnormalities

if taken in 3rd trimester - persistent pulmonary hypertension of the newborn

Question 6

what SSRI has the highest risk of congenital abnormalities if taken during pregnancy ?

Answer 6

paroxetine

Question 7

describe the monitoring of a patient who has been started on an SSRI.

Answer 7

after initiating treatment, patients should be reviewed after 2 weeks
if < 30yrs or high risk of suicide then follow up after 1 week

Question 8

what are symptoms of discontinuation syndrome and how is it prevented ?

Answer 8

GI symptoms: diarrhoea, pain, cramping, vomiting 
increased mood change 
difficulty sleeping 
sweating 
paraesthesia
restlessness 

reduce dose over 4 weeks when stopping SSRI

Question 9

a patient is on antidepressants for depression but has an MI.
what antidepressant would be more suitable to start post-MI?

Answer 9

sertraline (more evidence that it is safer)

Question 10

SSRI of choice if patient if already on warfarin or heparin ?

Answer 10

mirtazepine

Question 11

co-prescription with what drug increases risk of serotonin syndrome when taking SSRI ?

Answer 11

triptans

monoamine oxidase inhibitors (MOI’s)

Question 12

mechanism of mirtazepine ?

Answer 12

blocks alpha2-adrenergic receptors = increase neurotransmitter release

(NaSSA - noradrenergic and specific serotonin antidepressant)

Question 13

side effects of mirtazepine ?

Answer 13

sedation

weight gain

Question 14

benefits of mirtazepine ?

Answer 14

less side effects and drug interactions compared to other antidepressants

therefore useful in older people who may be on other medications or suffer from side effects

side effects of sedation and weight gain also beneficial in older people who suffer from insomnia and poor appetite

if patient is on warfarin/heparin - antidepressant of choice = mirtazepine

if patient has hepatic impairment - antidepressant of choice = mirtazepine

Question 15

what antidepressant can cause hypertensive crisis with tyramine containing foods?

Answer 15

non-selective MOI

Question 16

mechanism of MOI ?

Answer 16

inhibits monoamine oxidase which is responsible for the metabolism of serotonin and noradrenaline in the presynaptic cell

Question 17

antidepressant of choice in children and adolescents ?

Answer 17

SSRI - fluoxetine