B5.055 Prework 1: Adverse Drug Reactions Flashcards
(30 cards)
therapeutic dose of APAP
up to 4 g in 24 hr
most common cause of liver failure in western world
APAP overdose
what causes liver failure with APAP overdose
hepatic necrosis secondary to a cascade of signaling events resulting in mitochondrial injury and cell death
early signs of APAP overdose
none other than anorexia, nausea or vomiting
signs of APAP overdose after 24-48 hours
elevated PT or INR
increases transaminases
signs of APAP overdose after 48 hr to 7 days
increase in intracranial pressure
hepatic encephalopathy
coma
multi-organ failure
treatment of APAP overdose
gastric lavage with charcoal in early stages (rarely possible)
acetylcysteine (NAC) as antidote given in a dose according to nomogram based on plasma levels of APAP
IV glucose is hypoglycemic
long term- liver transplant
symptoms of salicylate oversode
tinnitus and dizziness
hyperpyrexia
coma, convulsions, resp failure with increasing dose
metabolic acidosis at later stages
discuss the causes of metabolic acidosis in salicylate overdose
uncoupling of oxidative phosphorylation
accumulation of keto acids
impairment of renal excretion of acids
depletion of bicarbonate reserve
treatment of salicylate overdose
gastric lavage if practical
correct hyperthermia by external cooling
treat resp depression with mechanical ventilation
administer IV fluids with glucose and lytes
give bicarb to alkalize the urine to promote excretion and help counteract acidosis ***
if renal function is impaired, dialysis to remove salicylates
what level of plasma salicylate indicates toxicity
50 mg/dL
3.5 nmol/L
sympathomimetics
cocaine
amphetamines
toxidrome for amphetamine abuse
tachycardia
hypertension
seizures
mydriasis (pupil dilation)
other symptoms of amphetamine abuse
CNS stimulation and muscle rigidity or hyperactivity
circulatory failure
coma
death
treatment of sympathomimetic overdose
maintain airway and respiration
control convulsions with diazepam IV
if oral intoxication > give activated charcoal and remove from stomach by lavage or emesis
succinylcholine is convulsions interfere w respiration
contraindications in sympathomimetic overdose
vasopressors hazardous (maintain bp with fluids) beta blockers
opioid toxidrome
unconsciousness
miosis
slow, shallow respirations
other symptoms of opioid overdose
cyanosis
hypotension
spasms of GI tract (spasticity and twitching of the muscles)
death from respiratory depression may occur within 2-4 hours
treatment of opioid overdose
maintain vitals
gastric lavage if oral ingestion
Naloxone is opioid antagonist (antidote), give repeat doses because short duration of action
maintain body warmth and fluid intake
symptoms of tricyclic antidepressant (amitriptyline) overdose
anticholinergic effects: tachycardia, dry mouth, nausea, confusion, urine retention
abnormal cardiac conduction, arrhythmias and hypotension
describe the cardiotoxic effects of amitriptyline
prolonged QT interval
blockade of myocardial fast sodium channels (QRS prolongation, tall R waves)
inhibition of potassium channels (QTc prolongation)
direct myocardial depression
blockade at M1, H1, and a-adrenergic receptors
treatment of tricyclic antidepressant overdose
maintain airway and assist ventilation
treat seizures with diazepam, pancuronium
give bicarb to maintain arterial pH between 7.45-7.55 to reverse cardiac membrane depressant effects
magnesium in severe cases
antiarrhythmic drugs contraindicated
B blocker cardiac disturbances
first degree heart block hypotension bradycardia AV block intraventricular conduction disturbances
ECG findings in b blocker overdose
normal QRS duration with increased PR intervals
QRS widening with massive intoxication
