Antidepressants Flashcards
mechanism of MAO A inhibitor toxicity
decreased amine degradation
amphetamine like effect and increaased catecholamine release
decreased amine reuptake
increased amine release
4 phases of MAOi overdose
- asymptomatic period up to 6-12 hr (monitor for 24hr post ingestion)
- neuromuscular excitation and symptathetic hyperactivity: HTN, tremor, seizure, rigid, agitation, hyperthermia, diaphoresis, myoclonus
- CNS depression and possible CV collapse - hypotension
- secondary complications for survivors
hypertension treatment in MAOi overdose
short actign agent for severe hypertension bc will go hypotensive after
hypotension use direct acting vasopressors
rigidity treatment in MAOi overdose
benzo
dantrolene
to prevent rhabdomyolysis bc severe muscle tension breaks down the muscles and gets stuck in kidneys
charcoal effective in MAOi overdose
yes
cause of eating indirect acting amines (cheese, fish) when on MAOi
peripheral hypertensive crisis
anticholinergic effects of tcas
agitation hallucination confusion sedation coma seizure hypertension tachycardia hyperthermia mydriasis dry flushing skin decreased GI motility urinary retention
TCA toxic effect - cardiovascular
QRS prolongation
sinus tachycardia
ventricular arrhythmias
hypotension
TCA toxic effect - CNS
coma
delerium
myoclonus
seizures
hyperthermia
ileus - lack of movement in intestines
urinary retention
risk factors increasing risk of toxicity in TCAs
pre existing heart conditions electrolyte abnormalities hepatic insufficiency stimulant drug use multiple drugs that increase QT intervals increased dose
general management of TCA overdose
airway IV line cardiac monitoring - EKG stomach lavage charcoal 50-100g + cathartic decreased LOC - oxygen, dextrose, naloxone, thiamine, ABG
toxic dose of tca
10-20mg/kg
limit rx to 1g
most common cause of death in tca overdose
refractory hypotension due to vasodilation or impaired cardiac contractility
treatment of orthostatic hypotension tca
intravascular volume expansion
sodium bicarb, vasopressors, or inotropes
correct hyperthermai, acidosis, seizures
treatment of cns effects in tca overdose
supportive
benzos
midazolam infusion for seizure, refractory barbiturates or propofol
not phenytoin due to arrhythmias