Antidepressants Flashcards
Which TCA is most likely to be useful in anxiety?
Clomipramine
What is TCA most often used for now?
Pain.
What is the first line medication used in generalised anxiety disorder?
Sertraline
What ECG changes are sometimes seen with tricyclic antidepressants? (in overdose)
Long QT
Wide QRS
Tachycardia
What are the 5 categories of antidepressants?
SSRI SNRI MAOI TCA novel/atypical
What are the 5 main SSRIs?
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Fluoxetine Fluvoxamine Escitalopram Paroxetine Citalopram Sertraline
How long should an antidepressant be trialled for before deeming as not working?
At least 2 months
What should you do if someone is on an antidepressant and its not working?
Titrate to the highest dose before switching or using adjuvant therapy.
What is the NNT for antidepressants to be successful?
3 (you need to treat 3 people to make one person better).
What does serotonin bind to?
5HT2 receptors
what are the 3 main neurotransmitters targeted by antidepressants?
serotonin
norepinephrine
Dopamine
What does serotonin do?
Regulates mood, feeding behaviour and emotions.
What causes the reuptake or serotonin?
Serotonin reuptake transporters.
When is SSRI used in depression?
As 1st line treatment.
How do SSRIs work?
Bind to serotonin reuptake transports and prevent them from removing serotonin from the synaptic cleft.
How long is it until improvements are seen with SSRI?
4-6 weeks
What can be treated with SSRI?
Depression
Eating disorders
Anxiety - PTSD, OCD
What are the side effects of SSRIs?
Increased risk of GI, cerebral and uterine bleeding (especially if on NSAIDs, aspirin and warfarin) Insomnia fatigue anxiety GI distress sexual dysfunction suicidal ideations serotonin syndrome restlessness nervousness sedation dizziness Hyponatraemia
What is the symptoms of activation syndrome seem with starting an SSRI?
Nausea
Anxiety
Panic
agitation
Usually lasts 2-10 days.
What are the pros of sertraline?
Weak P450 interactions
Short half life
Less sedating
What are the cons of sertraline?
Max absorption requires a full stomach.
What is the doses of sertraline?
starts at 50mg and goes up to 200mg.
What are the pros of fluoxetine?
Long half life (less chance of discontinuation syndrome + good for patients with compliance issues) Initially activating (increased energy)
What are the cons of fluoxetine?
Long half life (not good in hepatic illness)
P450 interactions
Initial activation syndrome - anxiety and insomnia
More likely to induce mania than other SSRIs.
What is serotonin syndrome?
When there is too much serotonin causing overstimulation of the nervous system.
What are the signs and symptoms of serotonin syndrome?
Skin flushing Coma Muscle rigidity Restlessness Nervousness Insomnia Fatigue Sedation Dizziness
How long does activation syndrome usually last for?
2-10 days
What cardiac side effects can be seen with citalopram?
QT prolongation
Can lead to arrhythmias.
What congenital problems can paroxetine cause?
Congenital heart defects.
Which SSRIs most commonly cause sedation and weight gain?
Paroxetine
What are the main 5 SRNIs?
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Duloxetine Desvenlafaxine Levomilnacipran Venlafaxine Milnacipran
Which two neurotransmitters do SRNIs target?
Serotonin
Norepinephrine
When is SRNI a go to medication?
When people haven’t responded to the SSRIs.
What are the side effects of SRNIs?
Insomnia Nausea Sexual dysfunction Hypertension Sweating Headaches
What are the pros of venlafaxine?
Minimal drug interactions No P450 activity Short half life Fast renal clearance (good for geriatrics)
What are the cons of venlafaxine?
Increase in diastolic blood pressure of 10-15mmHg.
QT prolongation.
What are the pros of duloxetine?
Less blood pressure changes than venlafaxine.
Which SRNI would be used first?
Duloxetine
What are the side effects of TCAs?
Weight gain Sleepy Dry mouth Blurred vision Lethal in overdose (even 7 days worth) Orthostatic hypotension Sedation Tachycardia Hallucinations Urinary retention Confusion
^Because they target so many receptors.
What is serotonin also known as?
5HT.
What is SERT?
Serotonin transporter (For reuptake)
What is NET?
Norepinephrine transporter (for reuptake).
What are the two groups of tricyclics?
Tertiary
Secondary (usually metabolites of the tertiary ones)
What does tertiary TCAs do?
Non-selective
Inhibit reuptake of serotonin AND norepinephrine
What do secondary TCAs do?
Selective
only inhibit reuptake of norepinephrine
How long is it before improvements are seen when using TCAs?
2-4 weeks
When are TCAs used?
Depression - if no response to SSRI and SRNI
Phobic disorders
Chronic neuropathic pain
Migraine prophylaxis
Which group of TCAs have more side effects?
Tertiary
Secondary has the same side effects but less severe.
Which receptors do TCAs block?
SERT NET Histamine - sedation Alpha 1 - orthostatic hypotension Muscarinic - dry mouth, tachycardia, hallucinations, urianry retention, confusion.
What cardio effects can TCAs cause?
Prolonged QT
Arrhythmias
What are the most common causes of death when using a TCA?
Convulsion
Coma
Cardio toxicity
How long should you wait when switching from an SSRI to MAOI?
2 weeks
fluoxetine - wait 5 weeks
When does TCA cause respiratory depression?
When taken with ethanol or sedative hypnotics
How do monoamine oxidase inhibitors work MAOIs?
By irreversibly binding to monoamine oxidase enzymes. Stops these enzymes from breaking down the neurotransmitters when they had been reuptook from the synaptic cleft.
Which type of depression responds well to MAOI?
Atypical depression
Resistant depression
What are the signs of atypical depression?
Able to improve their mood with positive events Increased appetite Weight gain Sleepiness Fatigue
What are the names of the non-selective MAOIs?
isocarboxazid
Phenelzine
Tranylcypromine
What are the selective MAOIs?
Only increase the level of dopamine
Selegiline
Rasagiline
What are selective MAOIs mostly used for?
Parkinsons.
What are the side effects of MAOIs?
Serotonin syndrome Hypertensive crisis Orthostatic hypertension Weight gain Dry mouth Sedation Sleep disturbance Sexual dysfunction
When are MAOIs used?
2nd or 3rd line.
How long most MAOIs be stopped for before starting another antidepressant?
At least 2 weeks. Takes 2 weeks for monoamine oxidase enzyme to come back.
Which category of MAOI is good for atypical depression?
Non selective MAOIs.
What are 2 serious side effects of MAOIs?
Serotonin syndrome
Hypertensive crisis
What are the signs and symptoms of hypertensive crisis?
Hyperthermia Hypertension Tachycardia agitation arrhythmias
What causes hypertensive crisis (cheese reaction) when taking MAOIs?
Eating tyrosine rich foods.
Wine
Cheese
Beer.
What is a common atypical antidepressant?
Mirtazapine
When is mirtazapine used?
Often in augmentation with SSRI
As a hypnotic at lower doses
How is treatment resistant depression treated?
Combination of antidepressants
Adjunctive therapy with lithium
Adjunctive therapy with atypical antipsychotics
ECT
Which type of antidepressants are best for anxiety?
More associated with serotonin:
SSRI
SRNI
(Antidepressants are 2nd line after psychological therapy).
How long should antidepressant prophylaxis be taken by?
1st episode - 6 months - 1 yr
2nd episode - 2 years
3rd episode - discuss life long therapy
Which antidepressant should not be used for panic disorder?
Fluoxetine
