Flashcards in Lec 74 Antidepressants Deck (60)
What is the phrase for anticholinergic toxicity?
red as a beet
dry as a bone
blind as a bat
mad as a hatter
hot as a hare
full as a flask
How are TCAs metabolized?
tertiary --> secondary
1/2 life 10-70 hrs
What drug-drug interactions with TCAs?
- block effect of antihypertensives
- additive tox with anti-arrhythmics/QTc prolonging agents, anticholinergics, CNS depressants, sympathomimetics
- drugs that increase TCA level: cimetidine, fluoxetine, ritonavir
- drugs that decrease TCA: carbamazepine, rifampin, phenytoin, nictonie, barbituates
MAOIs: wait 14 days between MAOI and TCA
What is dosing/monitoring of TCA?
- narrow therapeutic index
- similar dose range and plasma levels for most
- lower doses for pain
- unclear value in monitoring drug levels
What are uses for SSRIs?
- generalized anxiety
- panic disorder
- premenstrual dysphoric disorder
- social phobias
What is mech of action SSRIs?
bind to serotonin transporter and inhibit reuptake of 5HT into presynaptic nerve terminals
What is first aid mnemonic for SSRI names?
Flashbacks paralyze senior citizens
Which SSRI has highest potency for DA?
Which SSRIs have highest potency for NE?
Which SSRIs are most selective for 5HT reuptake?
What are common side effects of SSRIs?
sexual dysfunction (anorgasmia and decrease libido)
serotonin syndrome with any drug that increases 5HT [MAOI, SNRI, TCA] --> hyperthermia, confusion, myoclonus, flushing, diarrhea, seizures
What is treatment for serotonin syndrome?
cyproheptadine = 5HT2 receptor antagonist
What is metabolism of SSRI?
significant 1st pass
metabolized in liver by CYP enzymes
Which SSRIs have less drug-drug interactions?
citalopram and escitalopram
Which SSRIs have more drug drug interactions?
Which SSRI has longest half life and least withdrawal?
What are properties of fluoxetine?
- activating, may cause insomnia
- long half life
- least withdrawal symptoms
- more drug-drug interactions than others
What are properties of sertraline?
- mild DA reuptake inhibitor
What are properties of paroxetine?
- short half life
- withdrawal symptoms
- control release form available
- blocks NE reuptake, some anti-ACh activity, more sedation, dry mouth, weight gain
What happens in SSRI withdrawal? treat?
- if abrupt discontinuation after >6 wks of treatment
- dizziness, weakness, nausea, headache, anxiety, insomnia, paresthesias, flu-like symptoms, muscles aches
usually resolves within 3 wks
can treat with fluoxetine
What are advantages of SSRIs over older agents?
standard dosing = easy to titrate
often get clinical response at starting dose
usually not lethal in overdose
no arrhythmias/disturbance in BP/seizure/coma/resp depression
fewer drug-drug interactions
no special diet
What is use of SNRIs?
venlafaxine = also generalzie anxiety + panic disorders
duloxetine = also diabetic peripheral neuropathy
fibromyalgia, painful physical symptoms of depression, stress urinary incontinence, vasomotor symptoms
What is mech of SNRIs?
at low dose < 150mg/day act as SSRI
at higher doses --> SNRI = inhibit 5HT and NE reuptake
What are side effects of SNRIs?
increase BP [more in venlafaxine than duloxetine], stimulant effects, sedation, nausea
What is unique about bupropion's side effects?
no sexual dysfunction or weight gain
stimulant effects: tachycardia, insomnia; headache, seizure in bulimic pts
What are side effects of mirtazapine?
Sedation [may be desirable in depressed pts with insomnia]
increased appetite, weight gain [may be desirable in elderly or anorexic]
What is use of mirtazapine?
- appetite stimulation
Which anti-depressant is known for its priapism effects?
What causes the therapeutic delay in onset of antidepressant action?
downregulation of serotonergic receptors
may enhance neruonal regeneration process + restore cortical dendrites