Pharmacology Flashcards
Indication for antidepressants
Unipolar or Bipolar depression
Organic mood disorder
Schizoaffective disorder
Anxiety disorders
How long is the delay for effect in antidepressant medication?
3-6 weeks
How long should a patient persist with an antidepressant medication before considering a switch or augmenting?
At least 2 months
Types of Antidepressants
Tricyclics (TCA)
Monoamine Oxidase Inhibitors (MAOI)
Selective Serotonin Reuptake Inhibitors (SSRIs)
Serotonin/Noradrenaline Reuptake Inhibitors (SNRIs)
Novel antidepressants
What mechanism is used in Tricyclic Antidepressants?
Act mainly on serotonin receptors to inhibit serotonin and adrenaline
What side effects occur with TCAs?
Anticholinergic
Antiadrenergic
Antihistaminic
QT lengthening
Can be lethal in Overdose (OD)
Why are TCAs known to cause side effects?
Tertiary amine side chains prone to cross reaction with other receptors
Describe antihistaminic side effects seen in TCA use
Sedation
Weight gain
Describe anticholinergic side effects seen in TCA use
Dry mouth Dry eyes Constipation Memory deficits Delirium
Describe antiadrenergic side effects seen in TCA use
Orthostatic hypotension
Sedation
Sexual dysfunction
Examples of TCAs
Amipramine
Amitriptyline
Clomipramine
Doxepin
What are secondary TCAs and what is their mechanism of action?
Metabolites of tertiary amines
Block Noradrenaline
Examples of secondary TCAs
Desipramine
Nortriptyline
What is the mechanism of action of MAOIs?
Irreversible monoamine oxidase binding
Blocks Noradrenaline, dopamine and serotonin
Side effects of MAOIs
Orthostatic hypotension Weight gain Dry mouth Sedation Sexual Dysfunction Sleep disturbance
Hypertensive Crisis
Serotonin Sydrome
What can contribute to Hypertensive Crisis occuring with use of MAOIs?
Tyramine rich foods
Sympathomimetics
‘Cheese Reaction’ - red wine, processed meats, beans
What taken in addition to MAOIs can cause Serotonin Syndrome>
Medications increasing serotonin levels or sympathomimetics
Symptoms of Serotonin Syndrome
Abdominal pain Diarrhoea Sweats Tachycardia Hypertension Myoclonus Irritability Delirium
Cosequences of serotonin syndrome
Hyperpyrexia
Cardiovascular Shock
Death
Name a step to avoid Serotonin Syndrome
Wait period of 2 weeks before switching SSRI to MAOI
Except with fluoxetine- 5 week wait
SSRIs mechanism of action
Inhibit presynaptic serotonin reuptake
Side effects of SSRIs
GI upset
Sexual dysfunction
Anxiety Restlessness Insomnia Fatigue Sedation Dizziness