Psychiatry Flashcards
What region of the brain has been found to be hypometabolic in depression?
Hypermetabolic?
HypOmetabolic: Dorsolateral prefrontal cortex
HypERmegtabolic: Orbitofrontal cortex
What does MAO-A break down?
MAO-B?
MAO-A: Serotonin, dopamine, NE, tyramine
MAO-B: more selective for dopamine (also others including benzylamine and phenethylamine)
What amino acid are catecholamines derived from?
Tyrosine
Brain region most responisble for producing serotonin
Dorsal raphe (midbrain and pons
What receptors do triptans act at?
What non-neurologic effect do they have?
5-HT_1B and 5-HT_1D agonists
Vasoconstriction
Mechanism of action of ondansetron
5-HT3 receptor antagonist (this receptor is in the area postream)
Effects of serotonin outside the brain
- Vasoconstriction (5HT_1B and 5HT_1D)
- Platelet aggregation (5-HT_2A)
- Increased GI motility
- Bronchoconstriction
SSRIs with the least drug interactions
Citalopram and escitalopram (sertraline is also good)
Dopaminergic pathways. From where to where?
- Mesolimbic: midbrain to limbic system
- Mesocortical: midbrain to neocortex
- Nigrostriatal (SNc -> striatum)
- TUbuloinfundiblar (hypothalamus -> pituitary where inhibits prolactin release)
What receptors do TCAs act at other than serotonin?
Muscarinic
Alpha1-adrenergic
Histaminergic
(To varying degrees across medication)
Effect of TCAs on the bladder
Inhibit detrusor function and can lead to urinary retention (via antimuscarinic effects)
Which SSRI has the most anticholinergic activity
Paroxetine (so can lead to xerostomia and urinary retention)
Which first-generation antipsychotics have less antidopaminergic effects and more effects on muscarinic, adrenergic, and histaminergic receptors?
Chlorpromazine and thioridazine
What is another “high potency” first-generation antipsychotic, in addition to haloperidol?
Fluphenazine
Buspirone mechanism of action
5-HT_1A partial agonist (also some D2 antagonism)
What electrolyte effect can SSRIs have?
Which SSRIs are most prone to this?
Hyponatremia (especially in older individuals and those on diuretics)
Paroxetine and fluoxetine
What receptor does baclofen act at?
What type of receptor is this?
GABA_B agonist
Inhibitory GPCR (Gi) (Metabotropic)
(GABA_A, benzo target, is ionotropic and opens Cl- channels)
What receptor do benzos act at?
What type of receptor is this?
GABA_A agonist
Ionotropic (opens Cl- channels)
(GABA_B, baclofen target, is metabotropic GPCR, Gi)
Mirtazapine mechanism of action
Mixed:
1. Alpha-2 antagonism (leads to increased serotonin and NE release)
2. Antagonism at 5-HT2A, 5-HT2C, and 5-HT3 (but not 5-HT1 receptors, so these are still stimulated)
3. Antihistaminergic (sleep effect)
Receptor targets of trazodone
- 5-HT antagonism
- Antihistamine (sleep effect)
- Alpha1 antagonist
(Also weakly inhibits serotonin reuptake)
Which 2nd-gen antipsychotics are most and least likely to lead to weight gain?
Most: Clozapine and olanzapine
Least: Aripiprazole and ziprasidone
(Seroquel is in between)
Which antipsychotic is least likely to lead to QT prolongation?
Aripiprazole
Rare side effects of clozapine
- Myocarditis
- Agranulocytosis
Antipsychotic associated with increased seizure risk
Clozapine (and to a lesser extent olanzapine)
