Antidepressants Flashcards
How must you be diagnosed with depression
Symptoms must be present most of the day, nearly every day, for at least 2 weeks
Depression is a deficiency related to
Serotonin (5-HT), Norepinephrine (NE),
and Dopamine (DA)
Antidepressant Groups
Tricyclic antidepressants
Selective serotonin reuptake inhibitors (SSRIs)
Serotonin/norepinephrine reuptake inhibitors (S/NRIs)
Monoamine oxidase inhibitors (MAOIs)
Types of TCAs
Imipramine
Amitriptyline
When do you treat with TCAs
In patients unresponsive to SSRIs/SNRIs
How do TCAs work
Block neuronal reuptake of monoamine transmitters: norepinephrine (NE) and serotonin
Adverse effect of TCA
high overdose potential because it’s not specific
CARDIAC TOXICITY (!!!)
Similar to phenothiazine antipsychotics (3 rings)
TCAs
Toxicity of TCAs can cause
cardiotoxic actions
Have relatively few adverse effects due to their selectivity
SSRIs (and SNRIs)
Types of SSRIs
Fluoxetine (Prozac, Sarafem)
Sertraline (Zoloft)
How do SSRIs work
Produces selective inhibition of serotonin reuptake and produces CNS excitation
First line drugs for depression
SNRIs
Types of SNRIs
Venlafaxine (Effexor)
Duloxetine (Cymbalta)
How does Venlafaxine (Effexor) work
Blocks NE and serotonin uptake
(Does not block cholinergic, histaminergic, or alpha1-adrenergic receptors)
Serious complications if you combine Venlafaxine (Effexor) with
MAOIs
Mechanism of action for Duloxetine (Cymbalta)
Inhibits serotonin and NE reuptake
Weakly inhibits dopamine reuptake
Does not inhibit monoamine oxidase (MAO)
is responsible for the degradation of 5-HT
MAO
MAOIs mechanism of action
MAOIs irreversibly bind MAO-A and MAO-B (main isoform in serotonergic neurons)
Leads to increased availability of 5-HT and NE
Converts NE, serotonin, and dopamine into inactive products
Inactivates tyramine and other biogenic amines
These drugs are under-prescribed because of their drug-drug (or dietary) interactions
MAOIs
Types of MAOIs
Phenelzine non-selective
Selegiline (emsam) MAO-B selective
How are MOIs affected by antidepressants
Reversible and irreversible
* Reversible – lasts 3 to 5 days
* Irreversible – lasts about 2 weeks
All of the MAOIs in current use cause irreversible inhibition
