B4.014 Prework 1 Adverse Drug Reactions Flashcards
most common cause of acute liver failure in the Western world
acetaminophen
pathogenesis of APAP toxicity
hepatic necrosis secondary to cascade of signaling events resulting in mitochondrial injury and cell death
early APAP toxicity symptoms
none other than anorexia, nausea, or vomiting
24-48 hours after APAP poisoning
elevated PT or INR
increases transaminase levels
48 hours-7 days after APAP poisoning
increase in intracranial pressure hepatic encephalopathy coma multi-organ failure renal injury sepsis
therapeutic dose of APAP
4g in 24 h
very early stage treatment of APAP overdose
gastric lavage to remove tablets from stomach
antidote to APAP overdose
acetylcystein (NAC)
within 8-12 hours
adjust dose according to nomogram (plasma level and time postingestion)
may need IV glucose
long term treatment for APAP overdose
liver transplant
what is salicylate
anti-inflamm
common drug of overdose
signs of salicylate overdose
tinnitus (ringing of ears)
dizziness
hyperpyrexia (high temp)
coma, convulsions, resp failure w increasing dose
pathogenesis of salicylate overdose
metabolic acidosis due to accumulation of salicylic acid
- uncoupling of oxidative phosphorylation
- accumulation of keto acids
- impairment of renal excretion of acids
- depletion of bicarb reserve
treatment for salicylate overdose
gastric lavage if practical
correct hyperthermia by external cooling
resp distress with mechanical ventilation with O2
oral or IV fluids w/ glucose and electrolytes
dialysis if renal function impaired
how can you promote excretion and counter acidosis caused by salicylate overdose?
give sodium bicard
alkalize the urine
toxidrome for cocaine/amphetamines
tachycardia
hypertension
seizures
mydriasis
other symptoms of cocaine/amphetamine overdose
CNS stim and muscle rigidity or hyperactivity
v-tac or v-fib
circulatory failure
coma
what treatment is contraindicated in cocaine/amphetamine overdose?
beta blockers
how do you maintain BP with cocaine/amphetamine overdose?
fluids
vasopressors may be hazardous
how are convulsions controlled?
diazepam IV
succinylcholine if convulsions interfere with respiration
opioid triad/ toxidrome
unconsciousness
miosis (pin point pupils)
slow, shallow respiration
other symptoms of opioid overdose
cyanosis
hypotension
spasms of GI tract
death (resp depression or coma)
general treatments for opioid overdose
maintain vitals
gastric lavage/ induce emesis
maintain body warmth and adequate fluid intake
opioid antidote
naloxone (naltrexone)
need to give repeat doses because of short duration of action
examples of opioids
morphine
fentanyl
tramedol
most important consequences of tricyclic antidepressant (TCA) overdose
blockade of myocardial fast sodium channels (QRS prolongation, tall R wave in aVR)
inhibition of potassium channels
direct myocardial depression
TCA overdose symptoms
anticholinergic effects: tachycardia, dry mouth, nausea, confusion, urine retention
seizures
what types of cardio toxicity manifestations accompany TCA overdose
abnormal conduction
arrhythmias (prolonged QT)
hypotension
treatment for TCA overdoes
maintain airways and assist ventilation
diazepam for seizures
give sodium bicarb to maintain arterial pH between 7.45-7.55 to reverse cardiac membrane depressant effects (magnesium if severe)
counter indicated drugs for TCA overdose
class 1A antiarrhythmic drugs make torsade worse
suprapharmalogical effects of beta blocker overdose
first degree heart block hypotension bradycardia AV block intraventricular conduction disturbances
ECG findings in beta blocker overdose
normal QRS duration (widens with massive intoxication)
increased PR intervals
other symptoms of beta blocker overdose
CNS toxicity: convulsions, coma, resp arrest
bronchospasm in pts w preexisting asthma
hypoglycemia and hyperkalemia
treatment for beta blocker overdose
glucagon for bradycardia and hypotension
sodium bicarb for conduction defects
sotalol poisoning
torsade de pointe polymorphous ventricular tachycardia associated w QT prolongation
treated with: isoproterenol, magnesium
what can cause serotonin syndrome
SSRIs alone, or in combo with: MAOIs TCAs amphetamines opioids
common signs of serotonin syndrome
altered mental status fever agitation myclonus (muscle jerks) hyperreflexia ataxia diaphoresis (sweating)
serotonin antagonists
cyproheptadine
propranolol
