Antidepressants Flashcards
What are the indications for antidepressants?
Unipolar and bipolar depression Organic mood disorders Schizoaffective disorder Anxiety disorders, including -OCD -panic -social phobia -PTSD Premenstrual dysphoric disorder -impulsivity associated with personality disorders
What are the general guidelines for antidepressant prescription?
Choose agent based on
-past history of response
-side effect profile
-coexisting medical conditions
3-6 weeks after therapeutic dose achieved before improvement
If no improvement after 2 month at therapeutic dose, switch or augment
What are the classifications of antidepressants?
TCAs SSRIs SNRIs MAOIs Novel
Where to tertiary TCAs act?
Mainly serotonin receptors
What are examples of tertiary TCAs?
Amitriptyline
Imipramine
Where do secondary TCAs act?
Primarily blocking noradrenaline
What are examples of secondary TCAs?
Noritriptyline
Desipramine
In what type of TCAs are side effects more common?
Tertiary, due to side chain
What are the side effects of TCAs?
Antihistaminic- sedation, weight gain
Anticholinergic- dry mouth, blurred vision
Antiadrenergic- orthostatic hypotension, sexual dysfunction
QT lengthening
Lethal in overdose
What is the method of action of MAOIs?
Bind irreversible to monoamine oxidase, thereby preventing inactivation of amines, such as serotonin and dopamine
What ar the common side effects of MAOIs?
Orthoststic hypotension Weight gain Dry mouth Sedation Sexual dysfunction Sleep disturbance Hypertensive crisis when taken with tyramine rich foods or sympathomimetics (cheese)
What is the risk of side effects with MAOIs?
Common and severe
What drugs to MAOIs interact with?
Those that increase serotonin- serotonin syndrome
What are the signs and symptoms of serotonin syndrome?
Abdo pain Diarrhoea Sweats Tachycardia HTN Myoclonus Irritabiloty Delorium Can lead to hyperpyrexia, CV shock and death
What is the mode of action of SSRIs?
Block presynaptic serotonin reuptake
What are the 2 most common side effects of SSRIs?
GI upset
Sexual dysfunction
What are the symptoms of discontinuation syndrome of a SSRIs?
Agitation
Nausea
Disequilibrium
Dysphoria
What are some examples of SSRIs>
Sertraline- short half life, few drug interactions
Fluoxeine- long half life
Citalopram- few drug interactions, short half-life
Paroxetine- short half life, good for anxiety
What is the mode of action of SNRIs?
Inhibit both serotonin and noradrenergic reuptake
What are examples of SNRIs?
Venlafaxine
Duloxetine
What are the pros and cons of venlafaxine?
Minimal drug interactions and short half life
Sexual dysfunction and discontinuation syndrome
What are 2 novel antidepressants?
Buproprion
Mirtazepine
What are the pros and cons of bupropion?
Good augmenting agent
No weight gain, sexual side effects or sedation or cardiac interactions
Seizure risk at high dose
What is mirtazepine good for?
Augmenting SSRIs
What is the general protocol for antidepressant use?
Start on SSRI
Then move to SNRI
