Pharmacology/Psychiatry - Antidepressants Flashcards
Re-uptake inhibitors immediate action?
Increase levels of neurotransmitters = more opportunity to bind to receptor
Re-uptake inhibitors delayed action?
Down-regulation of neurotransmitter receptors
What might explain the reason for time needed to see antidepressant effect?
Re-uptake inhibitor delayed action - down-reg of NT receptors
Sustained antidepressant therapy is also associated with increase in production of what?
BDNF - brain derived neurotrophic factor
Antidepressant suicide risk is increased in which populations (in general)?
Children, adolescents, and adults up to 24 yo.
What are SNRI’s? Examples?
Serotonin and Norepinephrine Re-uptake Inhibitors
- Ex: Tricyclic Antidepressants (TCA) - amitriptyline
- Ex: Venlafaxine
What are SSRI’s? Example?
Selective Serotonin Re-uptake Inhibitors
- Ex: Fluoxetine
What are MAOI’s? Example?
Monoamine Oxidase Inhibitors
Ex: Trazodone
One of the first types of antidepressants discovered?
TCAs
Mechanism of TCAs?
They are classified as SNRI’s = block the re-uptake of serotonin and norepinephrine so they can hang around in synaptic cleft and exert their effects
Adverse effects of TCAs?
Block receptors for M-receptors, alpha-1 and Histamine-1 receptors
Adverse effect of blocking M-receptors? (4)
- Salivary glands = dry mouth
- Intestines = constipation
- Bladder = urinary retention
- Pupil = dilation
Adverse effect of blocking alpha-1 receptors on blood vessels? (3)
- Orthostatic hypotension
- Sedation
- Sexual dysfunction
Adverse effects of blocking histamine-1 receptors? (2)
- Weight gain
- Drowsiness
Sexual dysfunction is caused by serotonin acting on what receptor?
5-HT2a receptors
What can TCA overdose lead to?
Life-threatening cardiac arrhythmias
How does Venlafaxine differ from TCA’s?
- it also weakly inhibits dopamine re-uptake
- has less significant alpha-1, H-1 and M-1 block
Most commonly prescribed antidepressant class?
SSRI’s
Adverse effects of SSRI’s?
- Often related to M, alpha-1 and H-1 block but typically more mild than TCAs (except sexual dysfunction)
SSRI’s have the potential to cause what?
Serotonin syndrome
Triad of sx of serotonin syndrome?
- Altered mental status
- Autonomic hyperactivity
- Neuromuscular abnormalities
Altered mental status ex?
Agitation
Autonomic hyperactivity ex?
Patient is often hot and sweating with a fast HR and high BP
Neuromuscular abnormalities ex?
Hyper-reflexia and clonus are particularly common in lower extremities
