Antidepressants (Exam #1) Flashcards
What is the general NT abnormality in depression, and how do antidepressants work to fix this?
Decreased levels of monoamines (DA, NE or 5-HT)
- ALL antidepressants increase amine neurotransmission
What is the MOA of TCAs?
Inhibit NE and 5-HT reuptake
What is the MOA of SSRIs?
Selectively inhibit 5-HT reuptake
What is the MOA of SNRIs?
Inhibit NE and 5-HT reuptake
What is the MOA of MAOIs?
Inhibit reuptake of all 3 (DA, NE, 5-HT)
With reuptake inhibitors, what is an important characteristic that should be considered (and possibly relayed to the patient)?
Inhibition occurs immediately, but effects are DELAYED
Besides depression, what are three other uses of TCAs?
- Chronic pain (TMJ)
- Fibromyalgia
- Enuresis = DOC
What type of TCAs are Amitriptyline and Imipramine, and how does this affect their MOA?
Tertiary amines
- Inhibit 5-HT reuptake
What type of TCAs are Nortriptyline and Desipramine, and how does this affect their MOA?
Secondary amines
- Inhibit 5-HT reuptake
Are secondary or tertiary amine TCAs preferred, and why (2)?
Secondary = preferred
- Tertiary produce more seizures and are more sedating
How are TCAs metabolized?
CYP2D6 = drug interactions common
What seven AEs are commonly seen with TCAs?
- Drowsiness (histamines blocked)
- Constipation, dry mouth (cholinergic blocked)
- CV effects, arrhythmias (adrenergic blocked)
- Analgesia
- SIADH
- Sexual dysfunction
- Decreased seizure threshold
What is an important toxicity/overdose associated with TCAs? Ho do you treat it (3)? What there meds can be used to manage the arrhythmias?
Torsades de Pointe
- Treat with Mg, Isoproterenol, cardiac pacing
- For arrhythmias, use Lidocaine, Propranolol, Phenytoin
What is the most likely antidepressant to inhibit CYP2D6? What class is it a part of?
Fluoxetine (Prozac)
- SSRI
Which SSRI is preferred in the elderly?
Sertraline (Zoloft)
What is the current DOC for depression, and which two drugs specifically?
What is the LAST option for depression?
SSRIs
- Citalopram (Celexa)
- Escitalopram (Lexapro)
LAST option = MAOIs
If sexual dysfunction is present with an antidepressant, which drug can you switch to and why?
Buproprion
- Less sexual AEs
What are the two SNRIs? In what way might they be preferred to SSRIs, and how are they NOT preferred?
- Venlafaxine (Effexor)
- Duloxetine (Cymbalta)
Can be used for neuropathic pain BUT more AEs
What are two examples of MAOIs, and what is the MOA of each? Which is drug of last last choice?
Phenelzine = last last choice
- Inhibits MAO-A and MAO-B = increases all 3
Selegiline
- Inhibits MAO-B ONLY = increases DA only
Which type of MAOI has an AE of HTN crisis, and what drug is an example? What foods should be avoided?
Inhibits MAO-A
- Phenelzine
Avoid foods with Tyramine
What foods should be avoided with the use of Phenelzine and why?
Avoid foods with Tyramine
- Can cause HTN crisis because of MAO-A inhibition
What is the MOA of Buproprion, and what is its alternative use?
Inhibit DA
- Can be used for smoking cessation
What are the three AEs of Buproprion? In what instance might it be preferred to other antidepressants?
- Seizures
- CNS effects
- Cardiac
Sexual dysfunction RARE = preferred if present
What is the MOA of Mirtazapine, and what does this mean?
Blocks presynaptic a2 receptors
- Increase NE and 5-HT
