Antidepressants Flashcards
(99 cards)
1
Q
TCAs names
A
AmitripTYLINE
NortripTYLINE
LofePRAMINE
ImiPRAMINE
2
Q
TCAs MOA
A
5HT and NA reuptake inhibitor: compete for the binding site on the pre-synaptic neuron
3
Q
TCAs adverse effects
A
T - tremors
C - cardiac effects (postural hypotension and arrythmias)
A - anticholinergic effects (can’t spit, can’t shit, can’t see, can’t pee)
S - seizures and sedation
4
Q
Interactions of TCAs
A
T - catecholamines
C - catecholamines (BP), drugs that prolong QT e.g. amiodarone
A
S - sedatives e.g. ETOH, anxiolytics, opioids\
Also obviously SSRIs
5
Q
Suitability of TCAs in a suicide risk patient
A
Unsuitable - very dangerous in suicide risk…
Arrythmias mainly
6
Q
Contraindications of TCAs
A
T
C: heart block, post-MI
A: prostatism, glaucoma
S: epilepsy (caution)
7
Q
SSRIs names
A
Citalopram Fluoxetine Furoxamine Paroxetine Sertraline
Effective: escitalopram For: fluoxetine, furoxamine Sadness: sertaline Panic: paroxetine & Convulsions: citalopram
8
Q
SSRIs MOA
A
5-HT reuptake inhibitor
9
Q
SSRIs adverse effects
A
Stomach upset (N&V, GI dist) Stimulation of CNS (agitation, insomnia) Serotonin syndrome Reproductive disfunction in men (failure to orgasm, impotence) Insomnia
Also hyponatraemia, QT prolongation & lowers seizure threshold!
10
Q
Which antidepressant classes cause weight gain?
A
Munch More with MAOIs and Mirtazipine
11
Q
Which class is safest in suicide risk?
A
SSRIs
12
Q
Which class is contraindicated in under 18s?
A
SSRIs: increased risk of self-harm and suicidal thoughts
13
Q
Interactions of SSRIs?
A
Stomach upset: ANTIPLATELETS, ANTICOAGULANTS, NSAIDS
Stimulation of CNS: MAOIs, TRAMADOL, ANTIDEPRESSENTS
R
I
Seizures / sedation: ANTIDEPRESSANTS, ALCOHOL
14
Q
Which antidepressants shouldnt be given with NSAIDs or antiplatelets due to risk of GI bleeding?
A
SSRIs
15
Q
Which SSRIs inhibit CYP enzymes?
A
Fluoxetine
Paroxetine
Sertraline
16
Q
Which SSRI doesn’t inhibit CYP
A
Citalopram
17
Q
Which drug is first choice in cardiac disease?
A
Sertraline
18
Q
First choice post-MI?
A
Sertraline
19
Q
Main risk of SSRIs in OD?
A
Prolong QT -> arythmias
20
Q
Which SSRI can be stopped abruptly and why?
A
Fluoxetine due to long half life
21
Q
MAOIs names?
A
phenelzine
isocarboxazid
tranylcypromine
moclobemide
(all irrev except moclobemide)
22
Q
Which MAOI is still used more than the others?
A
Moclobamide - reversible MAO inhibitor
23
Q
MAOI MOA?
A
Block action of MAO-A (5HT metab) or MAO-B (phenylethylamine and DA metabolism)
24
Q
Indications for MAOI use?
A
Refractory depression, phobic patients, atypical features
25
AEs of MAOIs
Postural hypotension and dizziness
CNS stimulation: restlessness, insomnia, hallucinations
Weight gain
Anticholinergic effects
26
Which class shouldnt mature cheese be eaten with and why?
MAOIs
Cheese reaction: tyramine is a sympathomimetic and usually broken down in the gut by MAO. Tyramine rich foods therefore shouldnt be eaten as MAO can't break it down and it causes an acute hypertensive crisis
27
What is the cheese reaction?
Acute hypertensive crisis
Tyramine rich food such as mature cheese, beer, yeast etracts, pickled herring, cause an acute hypertensive crisis
28
Interactions of MAOIs
Pethidine
Antidepressants
Cheese reaction
Ephedrine containing products
29
If switching from moclobemide to another drug, what care needs to be taken?
2 week washout period before starting any other antidepressent
30
Mocobemide MOA
Selective reversible MAO-A inhibitor
31
Mirtazapine MOA
Blocks pre-synaptic alpha-2 receptor therefore prevents negative feedback loop and prevents inhibition of monoamine release, enhancing 5-HT and NA in the cleft
32
Trazodone MOA
Blocks action of 5-HT2a and 5-HT2c receptors to block 5-HT uptake
33
Adverse effects of mirtazipine?
Stimulates appetite and weight gain
Sedative
34
Which antidepressant might be good for elderly patient with recent weight loss
Mirtazipine - sedation and appetite stimulation
35
Trazodone adverse effects
Sedation ++
| Postural hypotension
36
SNRIs names
Vexed and depressed
Venlafaxine, desvenlafaxine, duloxetine
37
Indications of SNRIs
Anxiety (vexed)
| Depression (depressed)
38
SNRI adverse effects
S - same as SSRIs
H - hypertension
A - adrenergic effects (insomnia, anxiety, agitation)
T - tachycardia
39
Which SNRI inhibits CYP?
Duloxetine
40
Which antidepressant MAY have the greatest efficacy?
Venlafaxine above 150mg/day
41
Greatest risk of death in OD?
Venlafaxine
42
Least sedative antidepressant?
Imipramine or SSRI
43
Glaucoma or prostatism 1st line
Lofepramine
44
General first line
SSRI (citalopram)
45
CYP inhibitors SSRIs
fluoxetine
paroxetine
sertraline
(just not citalopram)
46
Highest suicide risks
TCAs and venlafaxine
47
Very rarely prescribed due to suicides
Dosulepin
48
Highest risk of discontinuation symptoms
Paroxetine and venlafaxine due to short half life
49
Can stop this SSRI abruptly
Fluoxetine
50
Switching MAOI, how?
2 week wash-out
51
Which of the TCAs are safer in OD that the others?
Lofeparamine
52
What is significant to tell a patient about antidepressants?
Not addictive
| Lag phase before therapeutic
53
How long before you review a non-suicidal patient newly started on ADs?
2 weeks
then 2-4 weekly for 3 months
then longer if stable
54
Why would you see certain groups of patients more often on starting new ADs, and how often?
- Under 30 (increased risk of suicidal idealities as an adverse effect of new treatment)
- High suicide risk patients
See them within a week
55
Patient is not responding to new antidepressant after 2 weeks... what do you do?
Ensure patient is taking correct dose and in the correct way, review in another week or 2
56
Patient is not responding to new antidepressant after 3-4 weeks... what do you do?
Consider increasing dose if no adverse effects
or switch to another antidepressant
57
You want to switch from the initial SSRI to another drug, what do you do?
- Another SSRI or well-tolerated newer generation AD
then if that fails
- a TCA or atypical e.g. venlafaxine
58
Which drugs must you take care when switching to a TCA?
Moclobemide: 2 week washout period
Fluoxetine + paroxetine: inhibit metabolism of TCAs
59
What drug has a half life of around 1 week and so you should be careful when switching to a new drug?
Fluoxetine (+ it inhibits TCA metabolism!)
60
Serotonin syndrome symptoms
WET DOG SHAKES
Shaking and trembling, diaphoresis
Anticholinergic but not dry as a bone, they're hot and wet!
1. Mental changes
confusion and agitation
delirium
progresses to lethargy and coma
```
2. Autonomic instability
shivering
sweating
changes in blood pressure
tachycardia
```
3. Neuromuscular hyperactivity
myoclonus
Hyperreflexia
Cogwheel rigidity
61
Three possible drugs to augment an antidepressant with?
Lithium
Antipsychotic (e.g. risperisone, olanzapine, quetiapine, ariprazole)
Another antidepressant e.g. mirtazapine
62
Mianserin
Serotonin and NA antagonist
& inhibits reuptake of NA
Causes dry mouth, constipation and sedation
NaSSA (Noradrenergic & specific serotonergic antidepressant)
63
Lithium cautions to take?
Pre treatment & 6 monthly:
- renal function
- thyroid function
After 1 week and then 3 monthly if stable:
- Lithium levels
If cardiovascular disease risk:
- ECG
64
What would you measure before commencement of lithium treatment? and when again?
Renal and thyroid function pre-treatment and 6 monthly
65
What would you measure after commencement of lithium treatment? and when again?
Lithium level after 1 week and then 3 monthly if stable
Same applies after every dose change
66
What would you monitor when a patient is on an antipsychotic?
- Weight
- Lipid levels
- Glucose levels
- Side effects e.g. EPS, hyperprolactinaemia
67
What side effects are common with antipsychotics? e.g. risperidone
Dopamine blockade therefore:
- EPS
- Hyperprolactinaemia: loss of libido, erectile dsyfunction, galactorrhea, amennorea
68
What advice would you give to a patient who is now feeling better after antidepressant pharmacological therapy?
- continue for 6 months
- not addictive
- greatly reduces relapse
- that psychological intervention now will minimise relapse risk
69
What are discontinuation symptoms?
```
Flu-like symptoms
Insomnia
Vivid dreams
Agitation
Irritability
GI disturbances
Cardiac arrythmias
Mania
```
Usually mild and self-limiting over around 1 week
70
How do you stop an antidepressant?
Usually tapering over around 4 weeks (or more) to minimise discontinuation symptoms
71
Which drug shouldnt be used with which antiplatelet and why?
Fluoxetine with clopidogrel, because it minimises antiplatelet effect
72
Which ADs inhibit CYP enzymes?
Fluoxetine
Sertraline
Paroxetine
Duloxetine
73
How long should a patient with depression/GAD/recurrent depression continue medicating after symptoms resolve?
Depression 6 months
GAD 12 months
Recurrent depression 2 years to lifelong
74
What does the "half triangle box" mean in the BNF?
Less suitable for prescribing; not first line but justifiable in certain circumstances.
E.g. meclobemide
75
Hyponatraemia... signs & symptoms, pathophysiology, cause, management, epidemiology?
```
Drowsiness
Confusion
Convulsions
Dizziness
Leg cramps
Muscle weakness
Nausea & vomiting
```
Without fever
Probably due to SiADH (therefore water retained so decreased Na+ in blood and increased Na+ in urine)
Caused by all antidepressants, mainly SSRIs
Managed by withdrawal of anti-depressant; if serum level below 125 requires treatment to correct hyponatraemia. Fluid restriction.
Daily sodium levels.
Once hyponatraemia is corrected, resume on a DIFFERENT antidepressant, possibly a TCA or MAOI to avoid SSRI relapse of hyponatremia.
Most commonly affects elderly, particularly elderly females.
76
Epidemiology of antidepressant induced hyponatraemia?
Most commonly affects elderly, particularly elderly females
Other risk factors include
- low body weight
- low baseline Na
- concurrent treatment
- reduced renal function
- co-morbidity
77
Signs & symptoms of hyponatraemia?
Consider in all patients who develop convulsions, confusion or drowsiness.
Also muscle cramps, weakness, nausea and vomiting, dizziness.
USUALLY WITHIN 14 DAYS OF STARTING ANTIDEPRESSANT.
78
Management of hyponatraemia?
Stop antidepressant.
Fluid restriction.
Monitor sodium levels daily.
If
79
Pathophysiology of hyponatraemia due to antidepressants?
Probably due to SiADH - increased H2O retention so low serum sodium
80
If patient has recurrent SiADH on several different ADs, what do you do?
Consider ECT
81
Who is more at risk of hyponatraemia due to ADs and why?
Elderly females;
Probably due to higher rates of co-morbidities and co-prescribed medications.
82
Which drug prolongs QT interval?
Citalopram (and escitalopram)
83
Which drugs lower seizure threshold?
SSRIs and TCAs
84
Which drugs would you give for an agitated or insomniac patient with a need for sedation?
Anxiolytic sedative e.g. amitryptiline
Mirtazipine
85
Mechanism of action of benzodiazepines
Bind to BZD site on GABAa receptor
Enhances capacity of GABA to open the chloride channel (inhibitory effect overall) - DOES NOT DIRECTLY OPEN CHLORIDE CHANNEL
Produces inhibitory neurotransmittion leading to sedation and reduction in anxiety
86
What sites are there on a GABA receptor?
- BZD
- GABAa
- Barbiturate
87
Where does alcohol act on the GABAa receptor?
Barbiturate site... hence barbiturates and alcohol more toxic in ODs
88
Effect of GABAa receptor activation?
Opening of chloride channel -> influx of chloride
Sedation
Amnesia
Muscle relaxation
Nervousness and anxiety reduced
89
Clinical uses of benzodiazepines?
Hypnotics are used to treat INSOMNIA
Anxiolytics are used to treat ANXIETY
SHORT TERM (2-4 week) relief of anxiety that is severe, disabling or causing unacceptable distress.
Not for mild anxiety.
Insomnia treatment only when SEVERE, DISABLING or causing ETREME DISTRESS.
90
Examples and characteristics of hypnotics?
Used to treat INSOMNIA
Short acting
Benzo's:
Temazepam
Nitrazepam (longer-acting)
Z-related compounds:
- zopiclone
- zolpidem
- zaleplon
91
Examples and characteristics of anxiolytic benzos?
Used to treat ANXIETY
Longer half life
Diazepam
Chlordiazepoxide
Lorazepam
Oxazepam
92
Which drug is indicated for poor sleep maintenance? (EMW)
Nitrazepam as longer acting
93
Adverse effect of nitrazepam particularly?
Hangover effect - next day
94
What hypnotics are there other than the benzos and how do they work?
Z-related compounds
- zopiclone
- zolpidem
- zaleplon
Act on same receptor as benzos but not benzos.
95
Adverse effects of benzos?
- Drowsiness and falls
- Judgment / dexterity impairment
- Increased RTA risk
- Hangover effect
- Forgetfulness
- Confusion
- Aggression
DEPENDENCE AND TOLERANCE
96
What is the big clinical consideration to take into account when prescribing benzodiazepines?
DEPENDENCE AND TOLERANCE
Develops within 3-14 days of continuous use
"Need" benzos to carry out normal day to day activities
May increase dosage stated on original prescription
Trouble stopping
97
How long does benzo tolerance / dependence take to develop?
3-14 days
98
Withdrawal from benzo effects?
```
Insomnia
Anxiety
Loss of appetite
Loss of weight
Tremor
Sweating
```
99
Abrupt withdrawal from benzos?
Confusion
Psychosis
Convulsions
Rebound anxiety
