Antidepressants Flashcards
Sertraline
fluoxetine
paroxetine
citalopram
are examples of what
selective serotonin re-uptake inhibitors (SSRI)
when starting an antidepressant what must you discuss with a patient
side effects therapeutic effects time taken to respond discontinuation symptoms safety net re suicide
what is the mechanism of action of an SSRI
selectively block serotonin (5-HT) reuptake from the synaptic cleft
what is the SSRI of choice in young people
fluoxetine
what are SSRIs used in
1st line in depression
also GAD, panic disorder, phobia, OCD
are SSRIs safe in overdose
yes
SSRIs are associated with withdrawal symptoms, how long should the dose be tapered off
4 weeks and taper more slowly towards the end
Can NSAIDs be given with an SSRI
advised against but can be, if they are need to co-prescribe a PPI
what drugs used in cardiology should be avoided with SSRIs
warfarin
heparin
aspirin
- consider mirtazapine instead
if an SSRI is used with a triptan or mono-oxidase inhibitor there is an increased risk of what
serotonin syndrome
what are the main side effects of SSRIs
GI upset - abdominal pain, constipation, nausea
GI bleeds
sexual dysfunction
headaches
mood: agitation/anxiety, increased suicidality in young people
hyponatraemia
insomnia
what is the concern with using SSRIs in the elderly
hyponatraemia and falls
what specific side effects do paroxetine cause
more weight gain and sexual dysfunction
increased withdrawal effect
what specific side effects do fluoxetine cause
insomnia
agitation
rash
what specific side effects do sertraline cause
diarrhoea
what specific side effects do citalopram cause
QT prolongation
which SSRI is cardioprotective and therefore useful after an MI
sertraline
what are the discontinuation symptoms of an SSRI
increased mood change restlessness difficulty sleeping/increased dreaming unsteadiness sweating paraesthesia GI symptoms
if someone is starting an SSRI what can you advise them about the side effects of GI upset e.g. cramping, constipation, nausea
normally settle within a few weeks
Amitriptyline, Norytrptiline, Lofepramine, Clomipramine imipramine, dosulepin, doxepin
are examples of what
tricyclic antidepressants
what is the mechanism of action of TCAs
Block the reuptake of noradrenaline and serotonin from the synapse (non-selectively, also block dopamine, histamine and muscarinic ACh receptors)
why do TCAs have an extensive side effect profile
also block dopamine, histamine and muscarinic ACh receptors
why might a TCA impact a patients ability to drive/operate machinery
sedative
are TCAs dangerous in overdose
yes - cardiotoxic
what are TCAs used for
depression (less commonly now due to side effect profile and toxicity in overdose)
neuropathic pain
anxiety
migraine prophylaxis
what are the side effects of TCAs
- sedation, weight gain
- dry mouth, constipation, blurred vision, urinary retention, sexual dysfunction
- QT prolongation, tachycardia, hypotension
venlafaxine and duloxetine are examples of what
serotonin and noradrenaline re-uptake inhibitors (SNRI)
what is the mechanism of action of SNRIs
selectively block noradrenaline and serotonin reuptake (weak dopamine blockade)
why are SNRIs preferable to TCAs
block major receptor blockade so reduced side effects
when are SNRIs used
second line to SNRI in depression
anxiety disorders
what are the side effects of SNRIs
GI upset
cardio - hypertension, palpitations, dizziness
what kind of drug is mirtazapine
noradrenaline and serotonin specific antidepressant - atypical
how does mirtazapine work
antagonises pre-synaptic noradrenaline, serotonin and histamine receptors
(a-2, 5ht2 and 5ht3 receptors)
why might mirtazapine be used and why
if patient experiencing weight loss and sleep disturbance - side effects include sedation and weight gain
when should mirtazapine be taken
evening
what are the side effects of mirtazapine
weight gain
sedation
what kind of drug is moclobemide
reversible monoamine oxidase inhibitor (MAOI)
what kind of drug is phenelzine
non-reversible mono-amine oxidase inhibitor
how do monoamine oxidase inhibitors (MAOI) work
block monoamine oxidase (MOA-A and MOA-B) which prevents the breakdown of serotonin and noradrenaline (along with other neurotransmitters)
what is a major adverse effect of monoamine oxidase inhibitors (MAOI) and how can it be avoided
hypertensive crisis (cheese reaction)
non-reversible MAOI prevents breakdown of dietary tyramine. Tyramine is a substrate of MAO. Accumulation of tyramine causes noradrenaline release causing BP to sky rocket
- avoid cheese, red wine and soy (food that contains dietary tyramine)
- patients must be off TCA/SSRI for several weeks before starting MAOI
what are the side effects of monoamine oxidase inhibitors (MAOI)
dizziness
postural hypotension
peripheral oedema
anticholinergic - dry mouth, constipation, blurred vision, urinary retention and sexual dysfunction
monoamine oxidase inhibitors (MAOI) are particularly good in what kind of depression
atypical depression
what kind of drug is trazadone
serotonin antagonist and reuptake inhibitor (SARI)
what is the mechanism of action of trazadone
potent serotonin and noradrenaline receptor antagonist
is trazadone addictive
no
what is the treatment of mild depression
active monitoring exercise guided self help CBT - antidepressants not generally recommended
what would a general treatment plan of depression look like
SSRI unless reason it cannot be given
if unsuccessful - increase dose or try a different SSRI
if unsuccessful can augment with other drug
