Antidepressants

Question 1

mechanism of MAO A inhibitor toxicity

Answer 1

decreased amine degradation
amphetamine like effect and increaased catecholamine release
decreased amine reuptake
increased amine release

Question 2

4 phases of MAOi overdose

Answer 2

1. asymptomatic period up to 6-12 hr (monitor for 24hr post ingestion)
2. neuromuscular excitation and symptathetic hyperactivity: HTN, tremor, seizure, rigid, agitation, hyperthermia, diaphoresis, myoclonus
3. CNS depression and possible CV collapse - hypotension
4. secondary complications for survivors

Question 3

hypertension treatment in MAOi overdose

Answer 3

short actign agent for severe hypertension bc will go hypotensive after
hypotension use direct acting vasopressors

Question 4

rigidity treatment in MAOi overdose

Answer 4

benzo
dantrolene
to prevent rhabdomyolysis bc severe muscle tension breaks down the muscles and gets stuck in kidneys

Question 5

charcoal effective in MAOi overdose

Answer 5

yes

Question 6

cause of eating indirect acting amines (cheese, fish) when on MAOi

Answer 6

peripheral hypertensive crisis

Question 7

anticholinergic effects of tcas

Answer 7

agitation
hallucination
confusion 
sedation
coma 
seizure
hypertension
tachycardia
hyperthermia
mydriasis
dry flushing skin
decreased GI motility 
urinary retention

Question 8

TCA toxic effect - cardiovascular

Answer 8

QRS prolongation
sinus tachycardia
ventricular arrhythmias
hypotension

Question 9

TCA toxic effect - CNS

Answer 9

coma
delerium
myoclonus
seizures

hyperthermia
ileus - lack of movement in intestines
urinary retention

Question 10

risk factors increasing risk of toxicity in TCAs

Answer 10

pre existing heart conditions
electrolyte abnormalities
hepatic insufficiency 
stimulant drug use 
multiple drugs that increase QT intervals
increased dose

Question 11

general management of TCA overdose

Answer 11

airway 
IV line 
cardiac monitoring - EKG
stomach lavage 
charcoal 50-100g + cathartic 
decreased LOC - oxygen, dextrose, naloxone, thiamine, ABG

Question 12

toxic dose of tca

Answer 12

10-20mg/kg

limit rx to 1g

Question 13

most common cause of death in tca overdose

Answer 13

refractory hypotension due to vasodilation or impaired cardiac contractility

Question 14

treatment of orthostatic hypotension tca

Answer 14

intravascular volume expansion
sodium bicarb, vasopressors, or inotropes
correct hyperthermai, acidosis, seizures

Question 15

treatment of cns effects in tca overdose

Answer 15

supportive
benzos
midazolam infusion for seizure, refractory barbiturates or propofol
not phenytoin due to arrhythmias

Question 16

tca cardiac cause of death

Answer 16

myocardial depression
ventricular tachycardia
ventricular fibrillation

Question 17

why do we do EKG in tca overdose

Answer 17

qrs duration >.10sec predictor of arrhythmias

serum concentrations not predictive

Question 18

treatment of cardiac toxicity in tca overdose

Answer 18

sodium bicarb narrows QRS reducing arrhythmias and hypotension
antiarrhythmics are contraindicated

Question 19

when is lipid rescue used

Answer 19

refractory cardiotoxicity for overdoses of lipophuilic meds (TCA, local anesthetic poisoning)
last ditch effort

Question 20

MOA of lipid rescue

Answer 20

lipid sink

drug stays in blood stream doesnt go to receptors

Question 21

length of tx in asymptomatic tca overdose

Answer 21

good once normal ECG x 6 hr with treatment GI decontamination

Question 22

length of treatment if symptomatic with altered mental status, seizue, cardiac dysrrhythmia

Answer 22

monitor in ICU 12-24hr after all symptoms resolved and all supportive interventions are discontinued
if all parameters norma then psychiatry to evaluate

Question 23

toxicity of antidepressants

Answer 23

1. amitriptyline
2. venlafaxine
3. mirtazapine
4. citalopram

Question 24

venlafaxine overdose

Answer 24

proarrhythmic
seizure
hypertension?
sinus tachycardia 
serotonin syndrome
blood pressure increased

Question 25

venlafaxine contraindicated in

Answer 25

high risk overdoses pre existing seizures and cardaic disease poor CYP2D6 metabolizers or drugs that inhibit this

Question 26

treatment of venlafaxine overdose

Answer 26

treat similar to TCA overdose | have to monitor for longer just in case a poor metabolizer

Question 27

venlafaxine metabolite

Answer 27

desvenlafaxine | toxicity seems low

Question 28

toxicity signs and symptoms of duloxetine

Answer 28

``` somnolence serotonin syndrome seizure vomiting QRS prolong and arrythmia low mostly neurologic and GI effects ```

Question 29

SSRI toxic effects

Answer 29

``` tremor sinus tachycardia NV diarrhea obtundation seizure serotonin syndrome ```

Question 30

treatment of SSRI toxicity

Answer 30

charcoal | supportive care

Question 31

tx of serotonin syndrome

Answer 31

supportive care neuromuscular - benzo increased temp - tylenol rigidity - dantrolene

Question 32

tx of severe symptoms in serotonin syndrome

Answer 32

cyproheptadine 4mg q4hr serotonin antagonism watch anticholinergic and antihistaminic properties

Question 33

signs and symptoms or serotonin syndrome

Answer 33

``` agitation confusion diaphoressi diarrhea fver shivering myoclonus tremor incoordination hyperreflexia ```

Question 34

citalopram only SSRI with cardiac toxicity what are the issues

Answer 34

dose related QT prolongation | increased risk of torsades de pointes

Question 35

bupropion safety

Answer 35

``` not a lot of cardiac issues seizures GI upset tahycardia agitation hypertension ```

Question 36

problems with XL bupropion

Answer 36

half life prolonged delayed transit time so more can be absorbed DELAYED HIGHER PEAK delayed onset seizures

Question 37

mirtazapine safety

Answer 37

tachycardia hypertension no cardiac issues or seizures watch for serotonergic and anticholinergic effects